When 'Permit Total Port Shutdown' feature in BIOS is enabled then Port Disable
bit is set in the Link Default Override Mask TLV PFA module in the NVM.
In this mode, the driver acts as if the link_active_on_if_down flag
is always disabled and disallow any change to that flag.
This feature applies for E830 and E835 NIC series.
Signed-off-by: Pawel Sobczyk <pawel.sobczyk@intel.com>