[MLIR][NVVM] Add test cases to check translation of matrix-multiply accumulate ops to the corresponding intrinsics in NVPTX backend

[navdeepkk]

Summary

Add test cases to check translation of the following NVVM ops:-

1.) wmma.m16n16k16.load
2.) wmma.m16n16k1616.store
3.) wmma.m16n16k16.mma

[ftynse]

Test cases must be added in the same commit as the code they are testing.

[bondhugula]

mlir/test/Target/nvvmir.mlir

76

You may want to add a short comment here as to the test.

[navdeepkk]

Closing revision as changes here were moved to D95331.