pch_gbe: scale time stamps to nanoseconds

This patch fixes the helper functions that give the transmit and
receive time stamps to return nanoseconds, instead of arbitrary clock
ticks.

[ RC - Rebased Takahiro's changes and wrote a commit message
  explaining the changes. ]

Signed-off-by: Takahiro Shimizu <tshimizu818@gmail.com>
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/ptp/ptp_pch.c b/drivers/ptp/ptp_pch.c
index 375eb04..847a3c3 100644
--- a/drivers/ptp/ptp_pch.c
+++ b/drivers/ptp/ptp_pch.c
@@ -261,6 +261,7 @@
 
 	ns = ((u64) hi) << 32;
 	ns |= lo;
+	ns <<= TICKS_NS_SHIFT;
 
 	return ns;
 }
@@ -277,6 +278,7 @@
 
 	ns = ((u64) hi) << 32;
 	ns |= lo;
+	ns <<= TICKS_NS_SHIFT;
 
 	return ns;
 }