ravb: Remove setting of RX software timestamp

ravb: Remove setting of RX software timestamp

The responsibility for reporting of RX software timestamp has moved to
the core layer (see __ethtool_get_ts_info()), remove usage from the
device drivers.

Reviewed-by: Carolina Jubran <[email protected]>
Reviewed-by: Rahul Rameshbabu <[email protected]>
Signed-off-by: Gal Pressman <[email protected]>
Reviewed-by: Niklas Söderlund <[email protected]>
Reviewed-by: Sergey Shtylyov <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>