linux-wandboard

drm/radeon/kms/atom: add crtc disable function

Disables the crts as per dpms and also disables the ppll
associated with the crtc.  This should save additional power.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>