ixgbe: Add a PHY power state method

ixgbe: Add a PHY power state method

Orabug: 21669416

This new method will control the PHY power state.  You pass in the
state you wish to change to (ether on or off).  For cases where this
method is not used the current PHY power state behavior is maintained.

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>
(cherry picked from commit 961fac889c0f2e1930092b6de00043cdd1cb2942)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>