drm/amdgpu: Use instance lookup table for GC 9.4.3

Register accesses need to be based on physical instance on bare metal.
Pass the right instance using logical to physical instance lookup
table before accessing registers. Add a macro GET_INST to get the right
physical instance of an IP corresponding to a logical instance.

v2: fix gfx_v9_4_3_check_rlcg_range() (Alex)

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Le Ma <Le.Ma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>