net: rcar_gen4_ptp: Remove unused defines

net: rcar_gen4_ptp: Remove unused defines

The driver specific flags to control packet time stamps have all been
replaced by values from enum hwtstamp_tx_types and enum
hwtstamp_rx_filters. Remove the driver specific flags as there are no
more users.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251104222420.882731-6-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>