drm/amdgpu: Initialize compute sdma and memory from kgd

v2: add missing MTYPE_NONCACHED enum

Signed-off-by: Ben Goz <ben.goz@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>