dt-bindings: memory: tegra30: emc: Document new interconnect property

External memory controller is interconnected with memory controller and
with external memory. Document new interconnect property which turns
External Memory Controller into interconnect provider.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201104164923.21238-11-digetx@gmail.comSigned-off-by: Krzysztof Kozlowski <krzk@kernel.org>

Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-emc.yaml

@@ -31,6 +31,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  "#interconnect-cells":
+    const: 0
+
   nvidia,memory-controller:
     $ref: /schemas/types.yaml#/definitions/phandle
     description:
@@ -214,6 +217,7 @@ required:
   - interrupts
   - clocks
   - nvidia,memory-controller
+  - "#interconnect-cells"
 
 additionalProperties: false
 
@@ -227,6 +231,8 @@ examples:
 
         nvidia,memory-controller = <&mc>;
 
+        #interconnect-cells = <0>;
+
         emc-timings-1 {
             nvidia,ram-code = <1>;