dt-bindings: ata: ahci-platform: Add rk3568-dwc-ahci compatible

Add SoC specific compatible for rk3568 ahci controller

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220311210357.222830-6-linux@fw-web.de

Author: frank-w

Documentation/devicetree/bindings/ata/ahci-platform.yaml

@@ -49,6 +49,10 @@ properties:
               - marvell,berlin2-ahci
               - marvell,berlin2q-ahci
           - const: generic-ahci
+      - items:
+          - enum:
+              - rockchip,rk3568-dwc-ahci
+          - const: snps,dwc-ahci
       - enum:
           - cavium,octeon-7130-ahci
           - hisilicon,hisi-ahci