sunxi: video: Add VGA output support

Add support for VGA directly from the sunxi SoC / display engine.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/configs/Cubietruck_defconfig b/configs/Cubietruck_defconfig
index b1f9f93..bc44410 100644
--- a/configs/Cubietruck_defconfig
+++ b/configs/Cubietruck_defconfig
@@ -1,6 +1,7 @@
 CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="AXP209_POWER,SUNXI_GMAC,RGMII,AHCI,SATAPWR=SUNXI_GPH(12),USB_EHCI"
 CONFIG_FDTFILE="sun7i-a20-cubietruck.dtb"
+CONFIG_VIDEO_VGA=y
 +S:CONFIG_ARM=y
 +S:CONFIG_ARCH_SUNXI=y
 +S:CONFIG_MACH_SUN7I=y