net: phy: qcom: add support for QCA807x PHY Family

This adds driver for the Qualcomm QCA8072 and QCA8075 PHY-s.

They are 2 or 5 port IEEE 802.3 clause 22 compliant 10BASE-Te,
100BASE-TX and 1000BASE-T PHY-s.

They feature 2 SerDes, one for PSGMII or QSGMII connection with
MAC, while second one is SGMII for connection to MAC or fiber.

Both models have a combo port that supports 1000BASE-X and
100BASE-FX fiber.

PHY package can be configured in 3 mode following this table:

              First Serdes mode       Second Serdes mode
Option 1      PSGMII for copper       Disabled
              ports 0-4
Option 2      PSGMII for copper       1000BASE-X / 100BASE-FX
              ports 0-4
Option 3      QSGMII for copper       SGMII for
              ports 0-3               copper port 4

Each PHY inside of QCA807x series has 4 digitally controlled
output only pins that natively drive LED-s.
But some vendors used these to driver generic LED-s controlled
by userspace, so lets enable registering each PHY as GPIO
controller and add driver for it.

These are commonly used in Qualcomm IPQ40xx, IPQ60xx and IPQ807x
boards.

Co-developed-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>