Warn for the wrong mask in enable only. Disable will have the wrong mask now
because the new state is committed before disabling the old state.

Changes since v1:
- Use crtc_mask (Durgadoss)
- Rebase.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457944075-14123-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>