net: ravb: convert to ndo_hwtstamp API

net: ravb: convert to ndo_hwtstamp API

Convert driver to use .ndo_hwtstamp_set()/.ndo_hwtstamp_get callbacks.
ravb_do_ioctl() becomes pure phy_do_ioctl_running(), remove it and
replace in callbacks.

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20251023220457.3201122-5-vadim.fedorenko@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>