ixgbe/base: new simplified X550em init flow

ixgbe/base: new simplified X550em init flow

The init flow is simplified. We no longer wait for the PHY FW init
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". SW no longer needs to put the PHY in
low-power mode or enable the transceiver.

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
Acked-by: Helin Zhang <helin.zhang@intel.com>