drm/edid: pass struct edid to connector_bad_edid()

Avoid casting here and there, and make it const.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4f9fdc961dfd9b36f4649e8ba57d05e43375fc92.1649685475.git.jani.nikula@intel.com