drm/vc4: Set up the AVI and SPD infoframes.

Fixes a purple bar on the left side of the screen with my Dell
2408WFP.  It will also be required for supporting the double-clocked
video modes.

Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/vc4/vc4_regs.h

@@ -441,6 +441,8 @@
 #define VC4_HDMI_RAM_PACKET_CONFIG		0x0a0
 # define VC4_HDMI_RAM_PACKET_ENABLE		BIT(16)
 
+#define VC4_HDMI_RAM_PACKET_STATUS		0x0a4
+
 #define VC4_HDMI_HORZA				0x0c4
 # define VC4_HDMI_HORZA_VPOS			BIT(14)
 # define VC4_HDMI_HORZA_HPOS			BIT(13)
@@ -502,6 +504,9 @@
 
 #define VC4_HDMI_TX_PHY_RESET_CTL		0x2c0
 
+#define VC4_HDMI_GCP_0				0x400
+#define VC4_HDMI_PACKET_STRIDE			0x24
+
 #define VC4_HD_M_CTL				0x00c
 # define VC4_HD_M_REGISTER_FILE_STANDBY		(3 << 6)
 # define VC4_HD_M_RAM_STANDBY			(3 << 4)