ARM: dts: Move am437x dss to the interconnect target module in l4

On am437x, the display subsystem (DSS) is on l4. We already have
the interconnect target module for it, so let's just move dss
there.

To do that, we need to adjust the module addresses for the ranges,
and use the ranges already added earlier based on reading the l4
interconnect instance AP registers.

Cc: Jyri Sarha <jsarha@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>