kernel: add pending mtk_sgmii and phy improvements from @lynxis

kernel: add pending mtk_sgmii and phy improvements from @lynxis

Add pending patches from Alexander 'lynxis' Couzens which are required
for RealTek NBase-T PHYs or SFP+ cages to work when connected to the
SGMII interface provided by recent MediaTek SoCs [1].
The patches for MT753x fix link speed limitation on CPU ports observed
by many users which is due to reset being carried out wrongly [2].

[1]: https://patchwork.kernel.org/project/netdevbpf/list/?series=669488&state=*
[2]: https://patchwork.kernel.org/project/netdevbpf/list/?series=669486&state=*

Signed-off-by: Daniel Golle <daniel@makrotopia.org>