mlxsw: spectrum_acl: Limit priority value

In Spectrum-2, higher priority value wins and priority valid values are in
the range of {1,cap_kvd_size-1}. mlxsw_sp_acl_tcam_priority_get converts
from lower-bound priorities alike tc flower to Spectrum-2 HW range. Up
until now tc flower did not provide priority 0 or reached the maximal
value, however multicast routing does provide priority 0.

Therefore, Change mlxsw_sp_acl_tcam_priority_get to verify priority is in
the correct range. Make sure priority is never set to zero and never
exceeds the maximal allowed value.

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>