drm/i915: Put fixed modes directly onto the panel's fixed_modes list

drm/i915: Put fixed modes directly onto the panel's fixed_modes list

Rather than having the connector init get the fixed mode back from
intel_panel and then feed it straight back into intel_panel_init()
let's just make the fixed mode lookup put the mode directly onto
the panel's fixed_modes list. Avoids the pointless round trip and
opens the door for further enhancements to the fixed mode handling.

v2: Make the debug message correct by using intel_panel_drrs_type() (Jani)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220331112822.11462-3-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>