selftests: mlxsw: Add a scale test for RIF MAC profiles

Query the maximum number of supported RIF MAC profiles using
devlink-resource and verify that all available MAC profiles can be utilized
and that an error is generated when user space tries to exceed this number.

Output example in Spectrum-2:

$ TESTS='rif_mac_profile' ./resource_scale.sh
TEST: 'rif_mac_profile' 4 [ OK ]
TEST: 'rif_mac_profile' overflow 5 [ OK ]

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>