FDT PHY API

I am working on a driver for one of the PCIe PHYs in the RK3588.

The driver needs to be able to find out the number of lanes to use from
the device tree node of the PCIe host controller that is connected to
the PHY.

Propose to modify the signature of the acquire() method of the
fdtbus_phy_controller struct to also pass in the phandle of the
device that wants to use the PHY.