sunxi: Display the board model on start-up

It is useful to know which sunxi board you are booting. Display this on
start-up to avoid confusion.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/configs/sunxi-common.h

@@ -174,6 +174,7 @@
 
 #define CONFIG_SYS_MONITOR_LEN		(768 << 10)	/* 768 KiB */
 #define CONFIG_IDENT_STRING		" Allwinner Technology"
+#define CONFIG_DISPLAY_BOARDINFO
 
 #define CONFIG_ENV_OFFSET		(544 << 10) /* (8 + 24 + 512) KiB */
 #define CONFIG_ENV_SIZE			(128 << 10)	/* 128 KiB */