drm/amdgpu: add RAS error count query for gfx_v9_4_3

Query GFX RAS ce/ue count.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>