ipq40xx: add Qualcomm QCA807x driver

ipq40xx: add Qualcomm QCA807x driver

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.

Each PHY inside of QCA807x series has 2 digitally controlled output only
pins that natively drive LED-s.
But some vendors used these to driver generic LED-s controlled by
user space, so lets enable registering each PHY as GPIO controller and
add driver for it.

This also adds the ability to specify DT properties so that 1000 Base-T
LED will also be lit up for 100 and 10 Base connections.

This is usually done by U-boot, but boards running mainline U-boot are
not configuring this yet.

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

Signed-off-by: Robert Marko <robert.marko@sartura.hr>