[][kernel][mt7981/mt7988][eth][mediatek-ge/soc: backport mediatek gphy support]

[Description]
Add mediatek-ge-soc.c:
1. Remove "/* Registers on MDIO_MMD_VEND1 */" macros and add a short
comment to show that we set default MLT3 shaper values for MT7988:
2. "How does 13 map to GBE: +7, TBT: +1, HBT: +4, TST: +7 ?"
delete above fine-tuning because we use 100% TX amplitude on MT7981 now.
3. Remove all "inline"s
4. Enable MEDIATEK_GE_SOC_PHY.

Before we use mediatek-ge-soc.c, we need to backport some newer APIs:
* [net-next,v7,00/10] introduce read_poll_timeout
https://patchwork.ozlabs.org/project/netdev/patch/20200323150600.21382-
2-zhengdejin5@gmail.com/
We pickup:
01/10 for read_poll_timeout(), needed by phy_read_mmd_poll_timeout()
02/10
03/10 for phy_read_mmd_poll_timeout(),
  needed by drivers/net/phy/mediatek-ge-soc.c
07/10 for phy_read_poll_timeout(), needed by drivers/net/phy/mxl-gpy.c
08/10
* [net-next,v3,0/3] add phy shared storage
https://patchwork.ozlabs.org/project/netdev/cover/20200506145315.13967-
1-michael@walle.cc/
We pickup 1/3 for phy_package_shared struct
* [net-next,v4,0/8] net: phy: mscc: PHC and timestamping support
https://patchwork.ozlabs.org/project/netdev/cover/20200623143014.47864-
1-antoine.tenart@bootlin.com/
We pick 1/8 for phy_package_probe_once()

mediatek-ge-soc.c file follows upstream code:
[net-next] net: phy: add driver for MediaTek SoC built-in GE PHYs
https://patchwork.kernel.org/project/linux-mediatek/patch/ZDihjfnzaZ1yh
9cT@makrotopia.org/

[Release-log]
N/A

Change-Id: I4de384b7430e22607c57a0d8ca931855b32340e2
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7374555
11 files changed