ixgbe: Fix 1G link WoL

We reset during the shutdown path which will reset AUTOC register.  This
would change LMS to 10G.  If we were currently linked at 1G we will lose
link, which is a bad thing if we wanted WoL to work.  For the fix I needed
to know if WoL is supported so I created a new bool in the ixgbe_hw struct.
If this is set we will not allow the reset to change the current LMS value
in AUTOC.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>