drm: Add link training repeaters addresses

DP 1.3 specification introduces the Link Training-tunable PHY Repeater,
and DP 1.4* supplemented it with new features. In the 1.4a spec, it was
introduced some innovations to make handy to add support for systems
with Thunderbolt or other repeater devices.

It is important to highlight that DP specification had some updates from
1.3 through 1.4a. In particular, DP 1.4 defines Repeater_FEC_CAPABILITY
at the address 0xf0004, and DP 1.4a redefined the address 0xf0004 to
DP_MAX_LANE_COUNT_PHY_REPEATER.

Changes since V4:
- Update commit message
- Fix misleading comments related to the spec version
Changes since V3:
- Replace spaces by tabs
Changes since V2:
- Drop the kernel-doc comment
- Reorder LTTPR according to register offset
Changes since V1:
- Adjusts registers names to be aligned with spec and the rest of the
  file
- Update spec comment from 1.4 to 1.4a

Cc: Abdoulaye Berthe <Abdoulaye.Berthe@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Abdoulaye Berthe <Abdoulaye.Berthe@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190909212144.deeomlsqihwg4l3y@outlook.office365.com

include/drm/drm_dp_helper.h

@@ -1008,6 +1008,32 @@
 #define DP_HDCP_2_2_REG_STREAM_TYPE_OFFSET	0x69494
 #define DP_HDCP_2_2_REG_DBG_OFFSET		0x69518
 
+/* Link Training (LT)-tunable PHY Repeaters */
+#define DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV 0xf0000 /* 1.3 */
+#define DP_MAX_LINK_RATE_PHY_REPEATER			    0xf0001 /* 1.4a */
+#define DP_PHY_REPEATER_CNT				    0xf0002 /* 1.3 */
+#define DP_PHY_REPEATER_MODE				    0xf0003 /* 1.3 */
+#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_TRAINING_PATTERN_SET_PHY_REPEATER1		    0xf0010 /* 1.3 */
+#define DP_TRAINING_LANE0_SET_PHY_REPEATER1		    0xf0011 /* 1.3 */
+#define DP_TRAINING_LANE1_SET_PHY_REPEATER1		    0xf0012 /* 1.3 */
+#define DP_TRAINING_LANE2_SET_PHY_REPEATER1		    0xf0013 /* 1.3 */
+#define DP_TRAINING_LANE3_SET_PHY_REPEATER1		    0xf0014 /* 1.3 */
+#define DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1	    0xf0020 /* 1.4a */
+#define DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1		    0xf0021 /* 1.4a */
+#define DP_LANE0_1_STATUS_PHY_REPEATER1			    0xf0030 /* 1.3 */
+#define DP_LANE2_3_STATUS_PHY_REPEATER1			    0xf0031 /* 1.3 */
+#define DP_LANE_ALIGN_STATUS_UPDATED_PHY_REPEATER1	    0xf0032 /* 1.3 */
+#define DP_ADJUST_REQUEST_LANE0_1_PHY_REPEATER1		    0xf0033 /* 1.3 */
+#define DP_ADJUST_REQUEST_LANE2_3_PHY_REPEATER1		    0xf0034 /* 1.3 */
+#define DP_SYMBOL_ERROR_COUNT_LANE0_PHY_REPEATER1	    0xf0035 /* 1.3 */
+#define DP_SYMBOL_ERROR_COUNT_LANE1_PHY_REPEATER1	    0xf0037 /* 1.3 */
+#define DP_SYMBOL_ERROR_COUNT_LANE2_PHY_REPEATER1	    0xf0039 /* 1.3 */
+#define DP_SYMBOL_ERROR_COUNT_LANE3_PHY_REPEATER1	    0xf003b /* 1.3 */
+#define DP_FEC_STATUS_PHY_REPEATER1			    0xf0290 /* 1.4 */
+
 /* DP HDCP message start offsets in DPCD address space */
 #define DP_HDCP_2_2_AKE_INIT_OFFSET		DP_HDCP_2_2_REG_RTX_OFFSET
 #define DP_HDCP_2_2_AKE_SEND_CERT_OFFSET	DP_HDCP_2_2_REG_CERT_RX_OFFSET