mlxsw: pci: Derive event type from event queue number

Due to a hardware issue in Spectrum-2, the field event_type of the event
queue element (EQE) has become reserved. It was used to distinguish between
command interface completion events and completion events.

Use queue number to determine event type, as command interface completion
events are always received on EQ0 and mlxsw driver maps completion events
to EQ1.

Fixes: c3ab4354

 ("mlxsw: spectrum: Extend to support Spectrum-2 ASIC")
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>