drm/amdgpu:bypass RLC init for SRIOV

one issue unresolved for RLC:
rlc will go wrong completely if there is a soft_reset
before RLC ucode loading.

to workaround above issue, we can totally ignore RLC
in guest driver side due to there was already full
initialization on RLC side by GIM

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Signed-off-by: Xiangliang Yu <Xiangliang.Yu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>