e1000e: Fix tight loop implementation of systime read algorithm

e1000e: Fix tight loop implementation of systime read algorithm

Orabug: 21792108

Change the algorithm. Read systimel twice and check for overflow.
If there was no overflow, use the first value.
If there was an overflow, read systimeh again and use the second
systimel value.

Signed-off-by: Raanan Avargil <raanan.avargil@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 37b12910dd11d9ab969f2c310dc9160b7f3e3405)
Signed-off-by: Brian Maly <brian.maly@oracle.com>