mlxsw: Configure egress FID classification after routing

After routing, a packet needs to perform an L2 lookup using the DMAC it got
from the routing and a FID. In unified bridge model, the egress FID
configuration needs to be performed by software.

It is configured by RITR for both sub-port RIFs and FID RIFs. Currently
FID RIFs already configure eFID. Add eFID configuration for sub-port RIFs.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>