dt-bindings: net: qca,ar803x: Add IPQ5018 Internal GE PHY support

dt-bindings: net: qca,ar803x: Add IPQ5018 Internal GE PHY support

Document the IPQ5018 Internal Gigabit Ethernet PHY found in the IPQ5018
SoC. Its output pins provide an MDI interface to either an external
switch in a PHY to PHY link scenario or is directly attached to an RJ45
connector.

The PHY supports 10/100/1000 mbps link modes, CDT, auto-negotiation and
802.3az EEE.

For operation, the LDO controller found in the IPQ5018 SoC for which
there is provision in the mdio-4019 driver.

Two common archictures across IPQ5018 boards are:
1. IPQ5018 PHY --> MDI --> RJ45 connector
2. IPQ5018 PHY --> MDI --> External PHY
In a phy to phy architecture, the DAC needs to be configured to
accommodate for the short cable length. As such, add an optional boolean
property so the driver sets preset DAC register values accordingly.

Signed-off-by: George Moussalem <george.moussalem@outlook.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20250613-ipq5018-ge-phy-v5-1-9af06e34ea6b@outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>