sunxi: Add A20-SOM204-EVB-eMMC board

A20-SOM204 board has option with onboard 16GB eMMC. The chip is wired
to MMC2 slot.

This patch adds defconfig and dts files for this board. The dts is same
with mainline kernel.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/board/sunxi/MAINTAINERS b/board/sunxi/MAINTAINERS
index ccf2eb8..6dd48c0 100644
--- a/board/sunxi/MAINTAINERS
+++ b/board/sunxi/MAINTAINERS
@@ -315,6 +315,7 @@
 M:	Stefan Mavrodiev <stefan@olimex.com>
 S:	Maintained
 F:	configs/A20-Olimex-SOM204-EVB_defconfig
+F:	configs/A20-Olimex-SOM204-EVB-eMMC_defconfig
 
 ORANGEPI WIN/WIN PLUS BOARD
 M:	Jagan Teki <jagan@amarulasolutions.com>