drm/dp: add LTTPR DP 2.0 DPCD addresses

DP 2.0 brings some new DPCD addresses for PHY repeaters.

Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/def17e2329722f22c35807be26b35590ccb93bfd.1631191763.git.jani.nikula@intel.com

include/drm/drm_dp_helper.h

@@ -1319,6 +1319,10 @@ struct drm_panel;
 #define DP_MAX_LANE_COUNT_PHY_REPEATER			    0xf0004 /* 1.4a */
 #define DP_Repeater_FEC_CAPABILITY			    0xf0004 /* 1.4 */
 #define DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT		    0xf0005 /* 1.4a */
+#define DP_MAIN_LINK_CHANNEL_CODING_PHY_REPEATER	    0xf0006 /* 2.0 */
+# define DP_PHY_REPEATER_128B132B_SUPPORTED		    (1 << 0)
+/* See DP_128B132B_SUPPORTED_LINK_RATES for values */
+#define DP_PHY_REPEATER_128B132B_RATES			    0xf0007 /* 2.0 */
 
 enum drm_dp_phy {
 	DP_PHY_DPRX,