ixgbe: add polling test to end of PHY reset

Some PHYs require that we poll the reset bit and wait for it to clear
before continuing initialization.  As such we should add this check to the
end of the ixgbe_reset_phy_generic routine.

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>