drm/i915/pfit: Check pfit destination window on ILK-BDW

The ILK-BDW panel fitter has several restrictions on the
destination window size. Check for those and reject the
configuration if things aren't entirely proper.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016143134.26903-7-ville.syrjala@linux.intel.com


Acked-by: Jani Nikula <jani.nikula@intel.com>