drm/amdgpu: Introduce SRIOV critical regions v2 during VF init

drm/amdgpu: Introduce SRIOV critical regions v2 during VF init

    1. Introduced amdgpu_virt_init_critical_region during VF init.
     - VFs use init_data_header_offset and init_data_header_size_kb
            transmitted via PF2VF mailbox to fetch the offset of
            critical regions' offsets/sizes in VRAM and save to
            adev->virt.crit_region_offsets and adev->virt.crit_region_sizes_kb.

Signed-off-by: Ellen Pan <yunru.pan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>