[] [add mt7986b-emmc-rfb project]

[Description]
Add mt7986b eMMC project

[Release-log]
N/A

Change-Id: I37cb0df722ba84a5c9d3eeb5a61629109bfcded9
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5000986
4 files changed