drm/display: Add missing Adaptive Sync DPCD definitions

The missing DPCD definitions from DP2.0 spec is as follows:

DOWNSPREAD_CTRL (107h):
	FIXED_VTOTAL_AS_SDP_EN_IN_PR_ACTIVE (bit 6)
		For sink devices that support Adaptive-Sync operation
		and Panel Replay

DPRX_FEATURE_ENUMERATION_LIST_CONT_1 (2214h):
	ADAPTIVE_SYNC_SDP_SUPPORTED (bit 0)
		Bit to check sink device has Adaptive-Sync capability
	AS_SDP_FIRST_HALF_LINE_OR_3840_PIXEL_CYCLE_WINDOW_NOT_SUPPORTED (bit 1)
		A sink device that clears this bit will generate VSync pulse
		leading edge of the HDMI output on the line count at which
		Adaptive-Sync SDP is received as long as source device transmits
		Adaptive-Sync SDP either in first line or first 3840 pixel cycles
		of the line whichever occurs first.
	VSC_EXT_SDP_FRAMEWORK_VERSION_1_SUPPORTED (bit 4)
		Bit to check sink device has SDP framework version 1 capability
Signed-off-by: Sung Joon Kim <Sungjoon.Kim@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

include/drm/display/drm_dp.h

@@ -603,6 +603,7 @@
 
 #define DP_DOWNSPREAD_CTRL		    0x107
 # define DP_SPREAD_AMP_0_5		    (1 << 4)
+# define DP_FIXED_VTOTAL_AS_SDP_EN_IN_PR_ACTIVE  (1 << 6)
 # define DP_MSA_TIMING_PAR_IGNORE_EN	    (1 << 7) /* eDP */
 
 #define DP_MAIN_LINK_CHANNEL_CODING_SET	    0x108
@@ -1105,6 +1106,11 @@
 # define DP_VSC_EXT_CEA_SDP_SUPPORTED			(1 << 6)  /* DP 1.4 */
 # define DP_VSC_EXT_CEA_SDP_CHAINING_SUPPORTED		(1 << 7)  /* DP 1.4 */
 
+#define DP_DPRX_FEATURE_ENUMERATION_LIST_CONT_1         0x2214 /* 2.0 E11 */
+# define DP_ADAPTIVE_SYNC_SDP_SUPPORTED    (1 << 0)
+# define DP_AS_SDP_FIRST_HALF_LINE_OR_3840_PIXEL_CYCLE_WINDOW_NOT_SUPPORTED (1 << 1)
+# define DP_VSC_EXT_SDP_FRAMEWORK_VERSION_1_SUPPORTED  (1 << 4)
+
 #define DP_128B132B_SUPPORTED_LINK_RATES       0x2215 /* 2.0 */
 # define DP_UHBR10                             (1 << 0)
 # define DP_UHBR20                             (1 << 1)