selftests: mlxsw: Test port range registers' occupancy

Test that filters that match on the same port range, but with different
combination of IPv4/IPv6 and TCP/UDP all use the same port range
register by observing port range registers' occupancy via
devlink-resource.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/0a2eb63b234fb062ff011e80231868cc80000c81.1689092769.git.petrm@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>