[PATCH] drm/atomic: Extract needs_modeset function

[Maarten Lankhorst]

Op 18-06-15 om 11:25 schreef Daniel Vetter:
> We use the same check already in the atomic core, so might as well
> make this official. And it's also reused in e.g. i915.
>
> Motivated by Maarten's idea to extract a connector_changed state out
> of mode_changed.
>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>
Reviewed-By: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>