[JITLink][MachO][AArch64] Specify endianness, fix name of testcase. (#168323)
The "MachO_ptrauth_noolloc_sections.yaml" testcase had a typo in the
name, and didn't explicitly specify its endianness. This was causing it
to fail when enabled on big endian platforms.
See conversation in https://github.com/llvm/llvm-project/pull/167902