The Intel i225 NIC has the possibility to add flex filters which can
match up to the first 128 byte of a packet. These filters are useful
for all kind of packet matching. One particular use case is Profinet,
as the different traffic classes are distinguished by the frame id
range which cannot be matched by any other means.

Add code to configure and enable flex filters.
Signed-off-by: NKurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NVinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: NDvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: NTony Nguyen <anthony.l.nguyen@intel.com>