ixgbe: fix X550 devices init flow

Reviewing the X550 copper init flow with the Si team resulted in a
new simplified flow.  We no longer wait for the PHY FW initialization
complete bit to be set as this bit is only set once by the PHY at power
on and then cleared on the first read. So only the first instance of
running SW (or possibly MAC FW) needs to initialize the PHY.

The PHY initialization has been simplified and now only requires that
the PHY FW be un-stalled
low-power mode or enabled the transceiver

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>