drm/i915/bios: document BDB versions of child device config fields

Document everything that was introduced after version 155, which seems
to be the baseline for some of the later documentation. No functional
changes.

Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
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/11e8200e750eea13604b2d21e56b37cd5e6d9ab0.1503600621.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_vbt_defs.h

@@ -285,15 +285,15 @@ struct common_child_dev_config {
 	u8 ddc_pin;
 	u16 edid_ptr;
 	u8 dvo_cfg; /* See DEVICE_CFG_* above */
-	u8 efp_routed:1;
-	u8 lane_reversal:1;
-	u8 lspcon:1;
-	u8 iboost:1;
-	u8 hpd_invert:1;
+	u8 efp_routed:1;					/* 158 */
+	u8 lane_reversal:1;					/* 184 */
+	u8 lspcon:1;						/* 192 */
+	u8 iboost:1;						/* 196 */
+	u8 hpd_invert:1;					/* 196 */
 	u8 flag_reserved:3;
-	u8 hdmi_support:1;
-	u8 dp_support:1;
-	u8 tmds_support:1;
+	u8 hdmi_support:1;					/* 158 */
+	u8 dp_support:1;					/* 158 */
+	u8 tmds_support:1;					/* 158 */
 	u8 support_reserved:5;
 	u8 aux_channel;
 	u8 dongle_detect;