drm/i915/bios: convert intel_bios_init_panel() to drm_edid

Try to use struct drm_edid where possible, even if having to fall back
to looking into struct edid down low via drm_edid_raw().

v2: Rebase

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/897807d62f74f690a173ecd405e25c6ccdd63b98.1674643465.git.jani.nikula@intel.com