e1000e: i219 - Increase minimum FIFO read/write min gap

e1000e: i219 - Increase minimum FIFO read/write min gap

Orabug: 21792108

Due to clocking changes in the Skylake platform, there was i219
data corruption. To work around this, HW team reported the need
to increase the minimum gap between the PHY FIFO read and write pointers.

Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@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 93cbfc709047a5bc3f8d86e0b55079b5077c8e00)
Signed-off-by: Brian Maly <brian.maly@oracle.com>