ixgbe: check EEPROM for WOL support for X540 and above

ixgbe: check EEPROM for WOL support for X540 and above

Orabug: 24568240

This change aims to simplify the logic we use to determine WOL
support by reading the EEPROM bits for MACs X540 and newer.

Also some cleanups in ixgbe_wol_supported() - changed return type to
bool and removed redundant return variable by simply using return after
the checks.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 740234f070eadd010f7b129c6592767db68f16ba)
Signed-off-by: Brian Maly <brian.maly@oracle.com>