i40e/i40evf: Use usleep_range() instead of udelay()

i40e/i40evf: Use usleep_range() instead of udelay()

As per the Documentation/timers/timers-howto.txt it is preferred to use
usleep_range() instead of udelay() if the delay value is > 10us in
non-atomic contexts.
So, replacing all the instances of udelay() with 10 or greater than 10
micro seconds delay in the driver and using usleep_range() instead.

Change-ID: Iaa2ab499a4c26f6005e5d86cc421407ef9de16c7
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Neerav Parikh <neerav.parikh@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>