add support for dw22d (image builder)

git clone https://github.com/zhouzhiwen2000/openwrt-dw22d.git

ImageBuilder:https://archive.openwrt.org/barrier_breaker/14.07/ramips/mt7620a/OpenWrt-ImageBuilder-ramips_mt7620a-for-linux-x86_64.tar.bz2

SDK:https://archive.openwrt.org/barrier_breaker/14.07/ramips/mt7620a/OpenWrt-SDK-ramips-for-linux-x86_64-gcc-4.8-linaro_uClibc-0.9.33.2.tar.bz2

tar jxvf OpenWrt-ImageBuilder-ramips_mt7620a-for-linux-x86_64.tar.bz2

tar jxvf OpenWrt-SDK-ramips-for-linux-x86_64-gcc-4.8-linaro_uClibc-0.9.33.2.tar.bz2

make DW22D FEEDS=1 RALINK=1

FEEDS=1 表示包含项目network-feeds 的功能在内

RALINK=1 表示包含5G驱动在固件中

Thanks to the project:rssnsj/openwrt-hc5x61/.