can: janz-ican3: add software tx timestamp

can: janz-ican3: add software tx timestamp

TX timestamps were added to the can_put_echo_skb() function of can_dev
modules in [1]. However, janz-ican3 does not rely on that function but
instead implements its own echo_skb logic. As such it does not offer
TX timestamping.

Add a call to skb_tx_timestamp() in the ican3_put_echo_skb() function
so that the module now supports TX software timestamps.

[1] commit f799fa169b39 ("can: dev: can_put_echo_skb(): add software
tx timestamps")
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f799fa169b39188971606586c8af0b81eaed7f27
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>