drm/i915/bios: Assume panel_type==0 if the VBT has bogus data

Just assume panel_type==0 always if the VBT gives us bogus data.
We actually already do this everywhere else except in
parse_panel_options() since we just leave i915->vbt.panel_type
zeroed. This also seems to be what Windows does.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220504150440.13748-6-ville.syrjala@linux.intel.com