drm/amdgpu: initialize umc ras function

support umc ras function initialization for aldebaran

v2: squash in compile fix

Signed-off-by: John Clements <john.clements@amd.com>
Signed-off-by: Stanley.Yang <Stanley.Yang@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>