eth: fbnic: add coverage for hw queue stats

eth: fbnic: add coverage for hw queue stats

This patch provides support for hardware queue stats and covers
packet errors for RX-DMA engine, RCQ drops and BDQ drops.

The packet errors are also aggregated with the `rx_errors` stats in the
`rtnl_link_stats` as well as with the `hw_drops` in the queue API.

The RCQ and BDQ drops are aggregated with `rx_over_errors` in the
`rtnl_link_stats` as well as with the `hw_drop_overruns` in the queue API.

ethtool -S eth0 | grep -E 'rde'
     rde_0_pkt_err: 0
     rde_0_pkt_cq_drop: 0
     rde_0_pkt_bdq_drop: 0
     ---
     ---
     rde_127_pkt_err: 0
     rde_127_pkt_cq_drop: 0
     rde_127_pkt_bdq_drop: 0

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250410070859.4160768-3-mohsin.bashr@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>