intel_drrs_init() is a mostly pointless wrapper around
intel_panel_add_edid_downclock_mode(), get rid of it.

The only really useful thing left in there is the debug
print regarding the DRRS type supported by the connector.
Let's just move that into intel_panel_init().
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220331112822.11462-5-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>