mlxsw: reg: Add Router Rules Copy Register

The RRCR register is used for copying and moving TCAM multicast routes
from different offsets. It will be used to allow routes relocation for
parman ops as part of the multicast router offloading logic.

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