dt-bindings: usb: samsung,exynos-dwc3 add exynos8890 compatible

Add a compatible for the exynos8890-dwusb3 node. It features the same
clocks and regulators as exynos7, so reuse its compatible.

Signed-off-by: Ivaylo Ivanov <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Acked-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/samsung,exynos-dwc3.yaml

···
           - samsung,exynos850-dwusb3
           - samsung,exynosautov920-dwusb3
       - items:
+          - const: samsung,exynos8890-dwusb3
+          - const: samsung,exynos7-dwusb3
+      - items:
           - const: samsung,exynos990-dwusb3
           - const: samsung,exynos850-dwusb3