dt-bindings: usb: samsung,exynos-usb2: include usb-hcd schema

Remove parts duplicated with usb-hcd.yaml DT schema and include it
directly.

Reviewed-by: Rob Herring <[e-mail]>
Reviewed-by: Alim Akhtar <[e-mail]>
Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/samsung,exynos-usb2.yaml

···
       - samsung,exynos4210-ehci
       - samsung,exynos4210-ohci
 
-  '#address-cells':
-    const: 1
-
   clocks:
     maxItems: 1
 
···
       Only for controller in EHCI mode, if present, specifies the GPIO that
       needs to be pulled up for the bus to be powered.
 
-  '#size-cells':
-    const: 0
-
-patternProperties:
-  "^.*@[0-9a-f]{1,2}$":
-    description: The hard wired USB devices
-    type: object
-    $ref: /usb/usb-device.yaml
-
 required:
   - compatible
   - clocks
···
   - phy-names
 
 allOf:
+  - $ref: usb-hcd.yaml#
   - if:
       properties:
         compatible:
···
       properties:
         samsung,vbus-gpio: false
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |