net: vlan: convert to ndo_hwtstamp_get() / ndo_hwtstamp_set()

8021q is one of the stackable net devices which pass the hardware
timestamping ops to the real device through ndo_eth_ioctl(). This
prevents converting any device driver to the new hwtimestamping API
without regressions.

Remove that limitation in the vlan driver by using the newly introduced
helpers for timestamping through lower devices, that handle both the new
and the old driver API.

Signed-off-by: Maxim Georgiev <glipus@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20230801142824.1772134-4-vladimir.oltean@nxp.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>