[AMDGPU][DOC][NFC] Add links to MI200 documentation

[kzhuravl]

LGTM, thanks

llvm/docs/AMDGPUUsage.rst

``gfx805``  - ``tongapro``  ``amdgcn``   dGPU                    - Offset        - *rocm-amdhsa* - FirePro S7150
                                                                                                         M7170
      ``gfx810``  - ``stoney``    ``amdgcn``   APU   - xnack           - Offset        - *rocm-amdhsa* *TBA*
                                                                         flat          - *pal-amdhsa*
                                                                         scratch       - *pal-amdpal*  .. TODO::
 
                                                                                                         Add product
                                                                                                         names.
 
-     **GCN GFX9 (Vega)** [AMD-GCN-GFX900-GFX904-VEGA]_ [AMD-GCN-GFX906-VEGA7NM]_ [AMD-GCN-GFX908-CDNA1]_
+     **GCN GFX9 (Vega)** [AMD-GCN-GFX900-GFX904-VEGA]_ [AMD-GCN-GFX906-VEGA7NM]_ [AMD-GCN-GFX908-CDNA1]_ [AMD-GCN-GFX90A-CDNA2]_
      -----------------------------------------------------------------------------------------------------------------------
      ``gfx900``                  ``amdgcn``   dGPU  - xnack           - Absolute      - *rocm-amdhsa* - Radeon Vega
                                                                         flat          - *pal-amdhsa*    Frontier Edition
                                                                         scratch       - *pal-amdpal*  - Radeon RX Vega 56
                                                                                                       - Radeon RX Vega 64
                                                                                                       - Radeon RX Vega 64
                                                                                                         Liquid
                                                                                                       - Radeon Instinct MI25
in this description.
     :doc:`GFX10<AMDGPU/AMDGPUAsmGFX10>` :doc:`gfx1011<AMDGPU/AMDGPUAsmGFX1011>`
 
                                         :doc:`gfx1012<AMDGPU/AMDGPUAsmGFX1011>`
     =================================== =======================================
 
 For more information about instructions, their semantics and supported
 combinations of operands, refer to one of instruction set architecture manuals
 [AMD-GCN-GFX6]_, [AMD-GCN-GFX7]_, [AMD-GCN-GFX8]_,
-[AMD-GCN-GFX900-GFX904-VEGA]_, [AMD-GCN-GFX906-VEGA7NM]_
-[AMD-GCN-GFX908-CDNA1]_, [AMD-GCN-GFX10-RDNA1]_ and [AMD-GCN-GFX10-RDNA2]_.
+[AMD-GCN-GFX900-GFX904-VEGA]_, [AMD-GCN-GFX906-VEGA7NM]_,
+[AMD-GCN-GFX908-CDNA1]_, [AMD-GCN-GFX90A-CDNA2]_, [AMD-GCN-GFX10-RDNA1]_ and
+[AMD-GCN-GFX10-RDNA2]_.
 
 Operands
 ~~~~~~~~
 
 Detailed description of operands may be found :doc:`here<AMDGPUOperandSyntax>`.
 
 Modifiers
 ~~~~~~~~~

 ========================
 
 .. [AMD-GCN-GFX6] `AMD Southern Islands Series ISA <http://developer.amd.com/wordpress/media/2012/12/AMD_Southern_Islands_Instruction_Set_Architecture.pdf>`__
 .. [AMD-GCN-GFX7] `AMD Sea Islands Series ISA <http://developer.amd.com/wordpress/media/2013/07/AMD_Sea_Islands_Instruction_Set_Architecture.pdf>`_
 .. [AMD-GCN-GFX8] `AMD GCN3 Instruction Set Architecture <http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_GCN3_Instruction_Set_Architecture_rev1.1.pdf>`__
 .. [AMD-GCN-GFX900-GFX904-VEGA] `AMD Vega Instruction Set Architecture <http://developer.amd.com/wordpress/media/2013/12/Vega_Shader_ISA_28July2017.pdf>`__
 .. [AMD-GCN-GFX906-VEGA7NM] `AMD Vega 7nm Instruction Set Architecture <https://gpuopen.com/wp-content/uploads/2019/11/Vega_7nm_Shader_ISA_26November2019.pdf>`__
 .. [AMD-GCN-GFX908-CDNA1] `AMD Instinct MI100 Instruction Set Architecture <https://developer.amd.com/wp-content/resources/CDNA1_Shader_ISA_14December2020.pdf>`__
+.. [AMD-GCN-GFX90A-CDNA2] `AMD Instinct MI200 Instruction Set Architecture <https://developer.amd.com/wp-content/resources/CDNA2_Shader_ISA_4February2022.pdf>`__
 .. [AMD-GCN-GFX10-RDNA1] `AMD RDNA 1.0 Instruction Set Architecture <https://gpuopen.com/wp-content/uploads/2019/08/RDNA_Shader_ISA_5August2019.pdf>`__
 .. [AMD-GCN-GFX10-RDNA2] `AMD RDNA 2 Instruction Set Architecture <https://developer.amd.com/wp-content/resources/RDNA2_Shader_ISA_November2020.pdf>`__
 .. [AMD-RADEON-HD-2000-3000] `AMD R6xx shader ISA <http://developer.amd.com/wordpress/media/2012/10/R600_Instruction_Set_Architecture.pdf>`__
 .. [AMD-RADEON-HD-4000] `AMD R7xx shader ISA <http://developer.amd.com/wordpress/media/2012/10/R700-Family_Instruction_Set_Architecture.pdf>`__
 .. [AMD-RADEON-HD-5000] `AMD Evergreen shader ISA <http://developer.amd.com/wordpress/media/2012/10/AMD_Evergreen-Family_Instruction_Set_Architecture.pdf>`__
 .. [AMD-RADEON-HD-6000] `AMD Cayman/Trinity shader ISA <http://developer.amd.com/wordpress/media/2012/10/AMD_HD_6900_Series_Instruction_Set_Architecture.pdf>`__
 .. [AMD-ROCm] `AMD ROCm™ Platform <https://rocmdocs.amd.com/>`__
 .. [AMD-ROCm-github] `AMD ROCm™ github <http://github.com/RadeonOpenCompute>`__