net: phy: microchip_t1: Adds support for lan887x phy

The LAN887x is a Single-Port Ethernet Physical Layer Transceiver compliant
with the IEEE 802.3bw (100BASE-T1) and IEEE 802.3bp (1000BASE-T1)
specifications. The device provides 100/1000 Mbit/s transmit and receive
capability over a single Unshielded Twisted Pair (UTP) cable. It supports
communication with an Ethernet MAC via standard RGMII/SGMII interfaces.

LAN887x supports following features,
- Events/Interrupts
- LED/GPIO Operation
- IEEE 1588 (PTP)
- SQI
- Sleep and Wakeup (TC10)
- Cable Diagnostics

First patch only supports 100Mbps and 1000Mbps force-mode.

Reviewed-by: Andrew Lunn <[email protected]>
Signed-off-by: Divya Koppera <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Divya-Koppera