ptp: gianfar: convert to the 64 bit get/set time methods.

The device features a 64 bit nanoseconds register, and so with this
patch the driver is ready for the year 2038.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/ethernet/freescale/gianfar_ptp.c
Simple merge