drm/i915/fb: Add debug spew for misaligned CC plane

drm/i915/fb: Add debug spew for misaligned CC plane

We're currently failing to provide any debug output when the
user passes in a misaligned offset for the clear color plane.
Add some debugs prints to make debugging actually possible.

Cc: Sagar Ghuge <sagar.ghuge@intel.com>
Cc: Nanley Chery <nanley.g.chery@intel.com>
Cc: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241129065014.8363-3-ville.syrjala@linux.intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>