tsnep: convert to ndo_hwtstatmp API

tsnep: convert to ndo_hwtstatmp API

Convert to .ndo_hwtstamp_get()/.ndo_hwtstamp_set() callbacks.
After conversions the rest of tsnep_netdev_ioctl() becomes pure
phy_do_ioctl_running(), so remove tsnep_netdev_ioctl() and replace
it with phy_do_ioctl_running() in .ndo_eth_ioctl.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Link: https://patch.msgid.link/20251016152515.3510991-7-vadim.fedorenko@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>