dt-bindings: host1x: Document new interconnect properties

Most of Host1x devices have at least one memory client. These clients
are directly connected to the memory controller. The new interconnect
properties represent the memory client's connection to the memory
controller.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201104164923.21238-17-digetx@gmail.com


Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>