drm/i915: Populate fb->format accurately in BIOS FB readout

drm/i915: Populate fb->format accurately in BIOS FB readout

Use drm_get_format_info() instead of drm_format_info() to populate
fb->format during the BIOS FB readout. The difference being that
drm_get_format_info() knows about compressed formats whereas
drm_format_info() doesn't.

This doesn't actually matter in practice since the BIOS FB should
never be compressed, but no reason we shouldn't use the more accurate
function here anyway.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251107181126.5743-4-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>