dt-bindings: usb: dwc2: document TPL support

The target peripheral list (TPL) is used to identify targeted devices
during Embedded Host compliance testing. The user can add "tpl-support"
in the device tree to enable it.
Document TPL support as described in usb-hcd.yaml.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220621152350.145745-4-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/dwc2.yaml

@@ -11,6 +11,7 @@ maintainers:
 
 allOf:
   - $ref: usb-drd.yaml#
+  - $ref: usb-hcd.yaml#
 
 properties:
   compatible:
@@ -161,6 +162,8 @@ properties:
       property is used.
     $ref: /schemas/graph.yaml#/properties/port
 
+  tpl-support: true
+
 dependencies:
   port: [ usb-role-switch ]
   role-switch-default-mode: [ usb-role-switch ]