sunxi: Add defconfig and dts for the Polaroid MID2809PXE4 tablet

The Polaroid MID2809PXE4 is a 9" tablet which is clearly marked
Polaroid MID2809PXE4 on the back. It features a 9" 16:9 800x480 LCD,
A23 Soc, 1GB RAM, 8GB NAND, gsl3670 touchscreen and esp8089 wifi.

The dts file is identical to the one submitted to the upstream kernel.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index ec99835..1a0d577 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -189,6 +189,7 @@
 dtb-$(CONFIG_MACH_SUN8I_A23) += \
 	sun8i-a23-evb.dtb \
 	sun8i-a23-gt90h-v4.dtb \
+	sun8i-a23-polaroid-mid2809pxe04.dtb \
 	sun8i-a23-q8-tablet.dtb
 dtb-$(CONFIG_MACH_SUN8I_A33) += \
 	sun8i-a33-ga10h-v1.1.dtb \