IB/mlx5: Expose more priorities for bypass namespace

BYPASS namespace is used by the RDMA side to insert flow rules into
the vport RX flow tables. Currently only 8 priorities are exposed,
increase this to 16 to allow more flexibility. This change will also
cause the BYPASS namespace to use 32 levels (as apposed to 16 today) of
flow tables, 16 levels for regular rules and 16 for don't trap rules.

Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>