net/mlx5e: E-switch, Add steering drop counters

Add flow counters to count packets dropped due to drop rules
configured in eswitch egress and ingress ACLs.
These counters will count VFs violations and incoming traffic drops.
Will be presented on hypervisor via standard 'ip -s link show' command.

Example: "ip -s link show dev enp5s0f0"

6: enp5s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 24:8a:07:a5:28:f0 brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast
    0          0        0       0       0       2
    TX: bytes  packets  errors  dropped carrier collsns
    1406       17       0       0       0       0
    vf 0 MAC 00:00:ca:fe:ca:fe, vlan 5, spoof checking off, link-state auto, trust off, query_rss off
    RX: bytes  packets  mcast   bcast   dropped
    1666       29       14         32      0
    TX: bytes  packets   dropped
    2880       44       2412

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>