dt-bindings: geni-se: Add interconnect binding for GENI QUP

Add documentation for the interconnect and interconnect-names properties
for the GENI QUP.

Signed-off-by: Akash Asthana <akashast@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rob Herring <robh@kernel.org>