drm/dp: Define protocol converter DPCD registers

DP 1.3 and 1.4 introduced some new registers for DP->HDMI protocol
converters. Define those.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-4-ville.syrjala@linux.intel.comReviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

include/drm/drm_dp_helper.h

@@ -984,6 +984,16 @@
 #define DP_CEC_TX_MESSAGE_BUFFER               0x3020
 #define DP_CEC_MESSAGE_BUFFER_LENGTH             0x10
 
+#define DP_PROTOCOL_CONVERTER_CONTROL_0		0x3050 /* DP 1.3 */
+# define DP_HDMI_DVI_OUTPUT_CONFIG		(1 << 0) /* DP 1.3 */
+#define DP_PROTOCOL_CONVERTER_CONTROL_1		0x3051 /* DP 1.3 */
+# define DP_CONVERSION_TO_YCBCR420_ENABLE	(1 << 0) /* DP 1.3 */
+# define DP_HDMI_EDID_PROCESSING_DISABLE	(1 << 1) /* DP 1.4 */
+# define DP_HDMI_AUTONOMOUS_SCRAMBLING_DISABLE	(1 << 2) /* DP 1.4 */
+# define DP_HDMI_FORCE_SCRAMBLING		(1 << 3) /* DP 1.4 */
+#define DP_PROTOCOL_CONVERTER_CONTROL_2		0x3052 /* DP 1.3 */
+# define DP_CONVERSION_TO_YCBCR422_ENABLE	(1 << 0) /* DP 1.3 */
+
 #define DP_AUX_HDCP_BKSV		0x68000
 #define DP_AUX_HDCP_RI_PRIME		0x68005
 #define DP_AUX_HDCP_AKSV		0x68007