Multicast routes actions may be updated after creation. An example for that
is an addition of an egress interface to an existing route.
So far, as tc flower API dictated, ACL rules were either created or
deleted. Since multicast routes in Spectrum-2 are written to ACL as any
rule, it is required to allow the update of a rule's action as it may
change.

Add methods and operations to support updating rule's action. This is
supported only for Spectrum-2.
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>