[][openwrt][common][bsp][Fix dsa patch format issue]

[Description]
Fix dsa patch format issue to make it also work on RDKB SDK

[Release-log]
N/A

Change-Id: Ibdb4773c940c4d005ef7d06fd370c760e6ebced7
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6956663
1 file changed