drm/amdgpu: Add new PF2VF flags for VF register access method

Add 3 sub flags to notify guest for indirect reg access of
gc, mmhub and ih

The host sets these flags depending on L1 RAP version,
asic and other scenarios. These flags ensure that
there is compatibility between different guest/host/vbios versions.

Signed-off-by: Rohit Khaire <rohit.khaire@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>