ARM: dts: Configure interconnect target module for dm814x cpsw

We can now probe devices with device tree only configuration using
ti-sysc interconnect target module driver. Let's configure the
module and drop the legacy "ti,hwmods" property.

As this module is very similar to what we already have configured
and working for am33xx, let's just update the whole cpsw with a
single patch to avoid some extra churn on the dts files.

Cc: Graeme Smecher <gsmecher@threespeedlogic.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>