sunxi: dts: Add a CONFIG_DEFAULT_DEVICE_TREE setting to all sunxi boards

This is a preparation patch for switching all sunxi boards over to using
the driver model.

Note that rather then defining both CONFIG_DEFAULT_DEVICE_TREE (for u-boot)
and CONFIG_FDTFILE (for the kernel), this commit simply replaces all
CONFIG_FDTFILE defconfig settings with CONFIG_DEFAULT_DEVICE_TREE and
uses CONFIG_DEFAULT_DEVICE_TREE for setting the default fdtfile env value
in sunxi-common.h .

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/configs/sunxi_Gemei_G9_defconfig b/configs/sunxi_Gemei_G9_defconfig
index 1e13fea..c46b725 100644
--- a/configs/sunxi_Gemei_G9_defconfig
+++ b/configs/sunxi_Gemei_G9_defconfig
@@ -6,7 +6,7 @@
 # More details are available at: http://linux-sunxi.org/Gemei_G9
 CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="AXP209_POWER,USB_EHCI"
-CONFIG_FDTFILE="sun4i-gemei-g9.dtb"
+CONFIG_DEFAULT_DEVICE_TREE="sun4i-a10-gemei-g9"
 CONFIG_VIDEO_LCD_MODE="x:1024,y:768,depth:18,pclk_khz:100000,le:799,ri:260,up:15,lo:16,hs:1,vs:1,sync:3,vmode:0"
 CONFIG_VIDEO_LCD_PANEL_LVDS=y
 CONFIG_VIDEO_LCD_POWER="PH8"