net/mlx5e: Don't allow forwarding between uplink

net/mlx5e: Don't allow forwarding between uplink

We can install forwarding packets rule between uplink
in switchdev mode, as show below. But the hardware does
not do that as expected (mlnx_perf -i $PF1, we can't get
the counter of the PF1). By the way, if we add the uplink
PF0, PF1 to Open vSwitch and enable hw-offload, the rules
can be offloaded but not work fine too. This patch add a
check and if so return -EOPNOTSUPP.

$ tc filter add dev $PF0 protocol all parent ffff: prio 1 handle 1 \
    flower skip_sw action mirred egress redirect dev $PF1

$ tc -d -s filter show dev $PF0 ingress
    skip_sw
    in_hw in_hw_count 1
    action order 1: mirred (Egress Redirect to device enp130s0f1) stolen
    ...
    Sent hardware 408954 bytes 4173 pkt
    ...

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>