net: phy: micrel: Add PTP support for lan8842

net: phy: micrel: Add PTP support for lan8842

It has the same PTP IP block as lan8814, only the number of GPIOs is
different, all the other functionality is the same. So reuse the same
functions as lan8814 for lan8842.
There is a revision of lan8842 called lan8832 which doesn't have the PTP
IP block. So make sure in that case the PTP is not initialized.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://patch.msgid.link/20250902121832.3258544-3-horatiu.vultur@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>