mlxsw: resource: Add resource identifier for port range registers

mlxsw: resource: Add resource identifier for port range registers

Add a resource identifier for maximum number of layer 4 port range
register so that it could be later used to query the information from
firmware.

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/59a8fec353d5ad9fbfb7612e4a7ff61eaedad445.1689092769.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>