net: ethernet: renesas: rcar_gen4_ptp: Move address assignment

net: ethernet: renesas: rcar_gen4_ptp: Move address assignment

Instead of accessing the Gen4 PTP specific structure directly in drivers
move the device address assignment into the preparation call. This is
done in preparation to completely hide the Gen4 PTP specific structure
from users.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://patch.msgid.link/20260201183745.1075399-2-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>