tg3: PTP - Enable the timestamping feature in hardware and fill skb tx/rx timestamps

This patch implements the hardware timestamping as described in
Documentation/networking/timestamping.txt

Update version to 3.128.

Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>