Double resets are required for recovery from certain error conditions.
Between resets, it is necessary to stall to allow time for any pending HW
events to complete. We use 1usec since that is what is needed for
ixgbe_disable_pcie_master(). The second reset then clears out any effects
of those events.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>