net: phy: BCM54210PE does not support PTP

BCM54213PE is an Ethernet PHY that supports PTP hardware timestamping.
BCM54210PW ia another Ethernet PHY, but one without PTP support.
Unfortunately the two PHYs return the same ID when queried, so some
extra information is required to determine whether the PHY is PTP-
capable.

There are two Raspberry Pi products that use these PHYs - Pi 4B and
CM4 - and fortunately they use different PHY addresses, so use that as
a differentiator. Choose to treat a PHY with the same ID but another
address as a BCM54210PE, which seems more common.

See: https://github.com/raspberrypi/linux/issues/5104



Signed-off-by: Phil Elwell <phil@raspberrypi.com>