mlxsw: pci: Fix size of trap_id field in CQE

The "trap_id" is 9bits long. So far, this was not a problem since we
used only traps with ids that fit into 8bits. But the ACL traps that are
going to be introduced use the 9th bit.

Fixes: eda6500a ("mlxsw: Add PCI bus implementation")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>