drm/amd/amdgpu: re-add missing GC 9.1 and SDMA0 4.1 sh_mask header files

These are required by umr to properly parse bitfield offsets.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexdeucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>