[llvm] [AMDGPU] Add support for HW_REG_WAVE_SCHED_MODE (PR #169840)

[via llvm-commits]

ronlieb wrote:

builders seem to be detecting errors in lit tests
  Failed Tests (5):
    LLVM :: MC/AMDGPU/gfx942_asm_features.s
    LLVM :: MC/AMDGPU/sopk-err.s
    LLVM :: MC/AMDGPU/sopk.s
    LLVM :: MC/Disassembler/AMDGPU/gfx11_dasm_sopk.txt
    LLVM :: MC/Disassembler/AMDGPU/gfx942_features.txt
  

https://github.com/llvm/llvm-project/pull/169840