drm/amdgpu: Add active_umc_mask to ras init_flags

Add active_umc_mask to ras init_flags.

Signed-off-by: Candice Li <candice.li@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>