drm/amdgpu: move umc ras irq functions to umc block

move umc ras irq functions from gmc v9 to generic umc block, these
functions are relevant to umc and they can be shared among all
generations of umc

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>