dt-bindings: connector: usb: add accessory mode description

Add description of the USB-C Accessory Modes supported on the particular
USB-C connector. This is required for devices like Qualcomm SM8150-HDK,
which have no other way to express accessory modes supported by the
hardware platform.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20231215173005.313422-2-dmitry.baryshkov@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/connector/usb-connector.yaml

@@ -171,6 +171,18 @@ properties:
       offer the power, Capability Mismatch is set. Required for power sink and
       power dual role.
 
+  accessory-mode-audio:
+    type: boolean
+    description: Whether the device supports Audio Adapter Accessory Mode. This
+      is only necessary if there are no other means to discover supported
+      alternative modes (e.g. through the UCSI firmware interface).
+
+  accessory-mode-debug:
+    type: boolean
+    description: Whether the device supports Debug Accessory Mode. This
+      is only necessary if there are no other means to discover supported
+      alternative modes (e.g. through the UCSI firmware interface).
+
   altmodes:
     type: object
     description: List of Alternative Modes supported by the schematics on the