drm/amdgpu: Fix SWS on multi-XCD GPU

GFX_9_4_3 supports multi-XCDs and multi-AIDs in one GPU device. SWS needs
to program IH_VMID_x_LUT with specified XCC instance and corresponded
AID instance.

Signed-off-by: Amber Lin <Amber.Lin@amd.com>
Reviewed-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>