dp83640: add time stamp insertion for sync messages

This commit adds one step support to the phyter. When enabled, the
hardware does not provide time stamps for transmitted sync messages but
instead inserts the stamp into the outgoing packet.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed