With the previous patch drm_atomic_helper_check_plane_state correctly
calculates clipping and the xf86-video-intel ddx is fixed to fall back
to GPU correctly when SetPlane fails, we can remove the hack where
we try to pan/zoom when out of min/max scaling range. This was already
poor behavior where the screen didn't show what was requested, and now
instead we reject it outright. This simplifies check_sprite_plane a lot.

Changes since v1:
- Set crtc_h to the height correctly.
- Reject < 3x3 rectangles instead of making them invisible for <gen9.
  For gen9+ skl_update_scaler_plane will reject them.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180503112217.37292-4-maarten.lankhorst@linux.intel.comAcked-by: Jani Nikula <jani.nikula@intel.com>