drm/i915/bios: Define VBT block 3 (Display Toggle Option) contents

Define the contents of VBT block 3 (Display Toggle Option).

On modern VBTs this is just a single byte, but on ALM there is
also some extra to do with toggle lists or something.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240503122449.27266-10-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_vbt_defs.h

@@ -141,7 +141,7 @@ struct bdb_header {
 enum bdb_block_id {
 	BDB_GENERAL_FEATURES		= 1,
 	BDB_GENERAL_DEFINITIONS		= 2,
-	BDB_OLD_TOGGLE_LIST		= 3,
+	BDB_DISPLAY_TOGGLE		= 3,
 	BDB_MODE_SUPPORT_LIST		= 4,
 	BDB_GENERIC_MODE_TABLE		= 5,
 	BDB_EXT_MMIO_REGS		= 6, /* VBIOS only */
@@ -561,6 +561,16 @@ struct bdb_general_definitions {
 	u8 devices[];
 } __packed;
 
+/*
+ * Block 3 - Display Toggle Option Block
+ */
+
+struct bdb_display_toggle {
+	u8 feature_bits;
+	u16 num_entries;					/* ALM only */
+	u16 list[];						/* ALM only */
+} __packed;
+
 /*
  * Block 9 - SRD Feature Block
  */