net: phy: mchp: Add support for LAN8814 QUAD PHY

net: phy: mchp: Add support for LAN8814 QUAD PHY

LAN8814 is a low-power, quad-port triple-speed (10BASE-T/100BASETX/1000BASE-T)
Ethernet physical layer transceiver (PHY). It supports transmission and
reception of data on standard CAT-5, as well as CAT-5e and CAT-6, unshielded
twisted pair (UTP) cables.

LAN8814 supports industry-standard QSGMII (Quad Serial Gigabit Media
Independent Interface) and Q-USGMII (Quad Universal Serial Gigabit Media
Independent Interface) providing chip-to-chip connection to four Gigabit
Ethernet MACs using a single serialized link (differential pair) in each
direction.

The LAN8814 SKU supports high-accuracy timestamping functions to
support IEEE-1588 solutions using Microchip Ethernet switches, as well as
customer solutions based on SoCs and FPGAs.

The LAN8804 SKU has same features as that of LAN8814 SKU except that it does
not support 1588, SyncE, or Q-USGMII with PCH/MCH.

This adds support for 10BASE-T, 100BASE-TX, and 1000BASE-T,
QSGMII link with the MAC.

Signed-off-by: Divya Koppera<divya.koppera@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>