Revert "kernel: backport MediaTek Ethernet PHY driver"

Revert "kernel: backport MediaTek Ethernet PHY driver"

This reverts commit 8b4cba53a9402f44da2dced4a78ca065b15dca94.

This broke the mt7530 on Linksys e8450 (mt7622) for me.
[    1.312943] mt7530 mdio-bus:00 lan1 (uninitialized): failed to connect to PHY: -EINVAL
[    1.320890] mt7530 mdio-bus:00 lan1 (uninitialized): error -22 setting up PHY for tree 0, switch 0, port 0
[    1.331163] mt7530 mdio-bus:00 lan2 (uninitialized): failed to connect to PHY: -EINVAL
[    1.339085] mt7530 mdio-bus:00 lan2 (uninitialized): error -22 setting up PHY for tree 0, switch 0, port 1
[    1.349321] mt7530 mdio-bus:00 lan3 (uninitialized): failed to connect to PHY: -EINVAL
[    1.357241] mt7530 mdio-bus:00 lan3 (uninitialized): error -22 setting up PHY for tree 0, switch 0, port 2
[    1.367452] mt7530 mdio-bus:00 lan4 (uninitialized): failed to connect to PHY: -EINVAL
[    1.375367] mt7530 mdio-bus:00 lan4 (uninitialized): error -22 setting up PHY for tree 0, switch 0, port 3
[    1.385750] mt7530 mdio-bus:00 wan (uninitialized): failed to connect to PHY: -EINVAL
[    1.393575] mt7530 mdio-bus:00 wan (uninitialized): error -22 setting up PHY for tree 0, switch 0, port 4

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>