mvebu: cortexa72: enable emmc feature

Enable "emmc" feature to use the emmc helpers on sysupgrade.

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>

target/linux/mvebu/cortexa72/target.mk

@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=aarch64
 BOARDNAME:=Marvell Armada 7k/8k (ARM64)
 CPU_TYPE:=cortex-a72
-FEATURES+=ext4
+FEATURES+=emmc ext4
 DEFAULT_PACKAGES+=e2fsprogs ethtool mkf2fs partx-utils
 
 KERNELNAME:=Image dtbs