mlxsw: spectrum: Add KVDL manager implementation for Spectrum-2

In Spectrum-2, KVD linear indexes are hashed into KVD hash. Therefore it
is possible for multiple resource types to use same indexes. There are
multiple index spaces. Also, the index space is bigger than the actual
KVD hash area, which allows to have holes in the index space without any
penalization. The HW has to be told in case the index for particular
resource type is no longer used so it can be freed from KVD hash. IEDR
register is used for that.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>