drm/amdgpu: create umc_v6_7_funcs for aldebaran

umc_v6_7_funcs are callbacks to support umc ras
functionalities in aldebaran

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: John Clements <John.Clements@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>