drm/i915: Fix plane state dumps

drm/i915: Fix plane state dumps

Stop dumping plane->state for planes. That is the old state most of the
time and dumping stale information only serves to confuse people.
Instead dump the new state just for the planes included in the
operation. For now we'll include only the planes for the modeset/fastset
pipes in the dumps. But probably we want to dump them all eventually,
just not quite sure how to present that information nicely to the user.

And while at it let's dump a few more interesting bits from the state.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190517193132.8140-14-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>