[][OpenWrt Dev][Mark image slot valid for mmc dual-boot upgrading]

[Description]
Add support for mmc dual-boot upgrading to mark image slot just updated valid

[Release-log]
N/A

Change-Id: I082175d2598d37a7462c5562815eacb175a3e390
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6105789
1 file changed