drm/amdgpu: sriov remove vcn_4_0 and jpeg_4_0

SRIOV needs to initialize mmsch instead of multimedia engines
directly. So currently remove them for SR-IOV until the code and
firmwares are ready.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Horace Chen <horace.chen@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>