kernel: add patch for YT8821 address collision

kernel: add patch for YT8821 address collision

This minimalistic patch should ensure that the Cudy M3000 with the
Motorcomm PHY works reliably. The patch is not upstreamable into the
mainline kernel. However, it could be sufficient as a simple stop-gap
measure until some other solution is found.

Link: https://forum.openwrt.org/t/cudy-m3000-with-motorcomm-phy-how-to-fix-it/247083?u=linuxtardis
Signed-off-by: Jakub Vaněk <linuxtardis@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/22259
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>