drm/amdgpu: move aca/mca init functions into ras_init() stage

adjust the function position to better match aca/mca fini code in ras_fini().

Signed-off-by: Yang Wang <kevinyang.wang@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>