[LLDB][MIPS] Fix some test case failures due to "elf_abi" field of qprocessInfo packet

[nitesh.jain]

The elf_abi field was introduced in qprocessInfo packet (commit rL284001) so that LLDB can set pointer size and parse aux vector accordingly. This patch fix some test cases failures by introducing this field in _KNOWN_PROCESS_INFO_KEYS.

lldb/trunk/packages/Python/lldbsuite/test/tools/lldb-server/gdbremote_testcase.py

_KNOWN_PROCESS_INFO_KEYS = [
         "effective-uid",
         "effective-gid",
         "cputype",
         "cpusubtype",
         "ostype",
         "triple",
         "vendor",
         "endian",
+        "elf_abi",
         "ptrsize"
     ]
 
     def parse_process_info_response(self, context):
         # Ensure we have a process info response.
         self.assertIsNotNone(context)
         process_info_raw = context.get("process_info_raw")
         self.assertIsNotNone(process_info_raw)