apalis_t30: add update_uboot wrapper

Add universal update_uboot wrapper that helps to update
U-Boot image on internal storage.

Create an proper tegra image:
$ cbootimage -s tegra30 apalis_t30.img.cfg apalis_t30.img

Flash in U-boot shell:
> tftpboot ${loadaddr} ${board_name}/${board_name}.img
> run update_uboot

Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
diff --git a/include/configs/apalis_t30.h b/include/configs/apalis_t30.h
index 821162a..701b34a 100644
--- a/include/configs/apalis_t30.h
+++ b/include/configs/apalis_t30.h
@@ -40,6 +40,17 @@
 #undef CONFIG_SYS_MAXARGS
 #define CONFIG_SYS_MAXARGS		32
 
+#define UBOOT_UPDATE \
+	"uboot_hwpart=1\0" \
+	"uboot_blk=0\0" \
+	"set_blkcnt=setexpr blkcnt ${filesize} + 0x1ff && " \
+		"setexpr blkcnt ${blkcnt} / 0x200\0" \
+	"update_uboot=run set_blkcnt && mmc dev 0 ${uboot_hwpart} && " \
+		"mmc write ${loadaddr} ${uboot_blk} ${blkcnt}\0" \
+
+#define BOARD_EXTRA_ENV_SETTINGS \
+	UBOOT_UPDATE
+
 #include "tegra-common-usb-gadget.h"
 #include "tegra-common-post.h"