mlxsw: spectrum_router: Expose RIF MAC profiles to devlink resource

Expose via devlink-resource the maximum number of RIF MAC profiles and
their current occupancy, so it can be used for debug and writing generic
tests, like in the next patch.

Example for Spectrum-2 output:

$ devlink resource show pci/0000:06:00.0
...
  name rif_mac_profiles size 4 occ 0 unit entry dpipe_tables none

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>