Add support for configuring PSFP stream filters (IEEE 802.1Q-2018,
8.6.5.1.1).

The VCAP CLM (VCAP IS0 ingress classifier) classifies streams,
identified by ISDX (Ingress Service Index, frame metadata), and maps
ISDX to streams.
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>