ARM: sunxi: Enable VGA bridge

Enable the VGA bridge used on the A13-Olinuxino in the sunxi defconfig
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/configs/sunxi_defconfig

@@ -98,6 +98,7 @@ CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
 CONFIG_DRM=y
+CONFIG_DRM_DUMB_VGA_DAC=y
 CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y