sunxi: enable ramdisk feature

Build initramfs images for this target.

Signed-off-by: Zoltan HERPAI <wigyori@uid0.hu>

Author: wigyori

target/linux/sunxi/Makefile

@@ -7,7 +7,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=arm
 BOARD:=sunxi
 BOARDNAME:=Allwinner ARM SoCs
-FEATURES:=ext4 display rootfs-part rtc squashfs usb usbgadget
+FEATURES:=ext4 display ramdisk rootfs-part rtc squashfs usb usbgadget
 SUBTARGETS:=cortexa8 cortexa7 cortexa53
 
 KERNEL_PATCHVER:=6.12