drm/atomic: Set all the changed flags in one place.

drm/atomic: Set all the changed flags in one place.

Now that handle_conflicting_encoders cannot disable crtc's any more
it makes sense to set all the changed flags in 1 place.
This makes the code slightly less magical.

The (now removed) comment is out of date. The only reason the
active_changed was set late was because handle_conflicting_encoders
could disable connectors. This is no longer the case,
and we can put everything in 1 place.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1491477543-31257-3-git-send-email-maarten.lankhorst@linux.intel.com