eth: bnxt: support per-queue statistics

Support per-queue statistics API in bnxt.

$ ethtool -S eth0
NIC statistics:
     [0]: rx_ucast_packets: 1418
     [0]: rx_mcast_packets: 178
     [0]: rx_bcast_packets: 0
     [0]: rx_discards: 0
     [0]: rx_errors: 0
     [0]: rx_ucast_bytes: 1141815
     [0]: rx_mcast_bytes: 16766
     [0]: rx_bcast_bytes: 0
     [0]: tx_ucast_packets: 1734
...

$ ./cli.py --spec netlink/specs/netdev.yaml \
   --dump qstats-get --json '{"scope": "queue"}'
[{'ifindex': 2,
  'queue-id': 0,
  'queue-type': 'rx',
  'rx-alloc-fail': 0,
  'rx-bytes': 1164931,
  'rx-packets': 1641},
...
 {'ifindex': 2,
  'queue-id': 0,
  'queue-type': 'tx',
  'tx-bytes': 631494,
  'tx-packets': 1771},
...

Reset the per queue counters:
$ ethtool -L eth0 combined 4

Inspect again:

$ ./cli.py --spec netlink/specs/netdev.yaml \
   --dump qstats-get --json '{"scope": "queue"}'
[{'ifindex': 2,
  'queue-id': 0,
  'queue-type': 'rx',
  'rx-alloc-fail': 0,
  'rx-bytes': 32397,
  'rx-packets': 145},
...
 {'ifindex': 2,
  'queue-id': 0,
  'queue-type': 'tx',
  'tx-bytes': 37481,
  'tx-packets': 196},
...

$ ethtool -S eth0 | head
NIC statistics:
     [0]: rx_ucast_packets: 174
     [0]: rx_mcast_packets: 3
     [0]: rx_bcast_packets: 0
     [0]: rx_discards: 0
     [0]: rx_errors: 0
     [0]: rx_ucast_bytes: 37151
     [0]: rx_mcast_bytes: 267
     [0]: rx_bcast_bytes: 0
     [0]: tx_ucast_packets: 267
...

Totals are still correct:

$ ./cli.py --spec netlink/specs/netdev.yaml --dump qstats-get
[{'ifindex': 2,
  'rx-alloc-fail': 0,
  'rx-bytes': 281949995,
  'rx-packets': 216524,
  'tx-bytes': 52694905,
  'tx-packets': 75546}]
$ ip -s link show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 14:23:f2:61:05:40 brd ff:ff:ff:ff:ff:ff
    RX:  bytes packets errors dropped  missed   mcast
     282519546  218100      0       0       0     516
    TX:  bytes packets errors dropped carrier collsns
      53323054   77674      0       0       0       0

Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Amritha Nambiar <amritha.nambiar@intel.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240306195509.1502746-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>