arm64: zynqmp: Describe TI phy as ethernet-phy-id

TI DP83867 is using strapping based on MIO pins. Tristate setup can
influence PHY address. That's why switch description with ethernet-phy-id
compatible string which enable calling reset. PHY itself setups phy address
after power up or reset. Phy reset is done via gpio.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/b49904649a363f40dc9c4d3fa275e42129562082.1684767562.git.michal.simek@amd.com