Revert "drm/amd/display: Don't load DMCU for Raven 1"

This reverts commit 55143dc2.

This causes build breakags with some Kconfigs so revert for now.

Fixes: 55143dc2

 ("drm/amd/display: Don't load DMCU for Raven 1")

Signed-off-by: Dave Airlie <airlied@redhat.com>