mlxsw: spectrum_flow: Promote binder-type dispatch to spectrum.c

Two RED qevents have been introduced recently. From the point of view of a
driver, qevents are simply blocks with unusual binder types. However they
need to be handled by different logic than ACL-like flows.

Thus rename mlxsw_sp_setup_tc_block() to mlxsw_sp_setup_tc_block_clsact()
and move the binder-type dispatch from there to spectrum.c into a new
function of the original name. The new dispatcher is easier to extend with
new binder types.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>