[][kernel][common][eth][Add netdev_upper_dev_link feature to the dsa_slave_create() function]

[Description]
Add netdev_upper_dev_link feature to the dsa_slave_create() function.

This feature is a backport from kernel-5.15 that can assist the DSA
driver in managing the lower/upper interface.

[Release-log]
N/A


Change-Id: Idcc06ff70dc6fb2d6a4f98496ea8377ebea4def1
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8357223
2 files changed