arm64: dts: rockchip: enable DP for rk3399-gru

Enable cdn_dp and create a cdn-dp-sound for the DP audio. Delete the
endpoints between dp and vopL for gru, since we want the DP only use
VOP big, which can support 4K mode.
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
[dropped vop-hacks]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi

@@ -515,10 +515,15 @@ sound {
 		compatible = "rockchip,rk3399-gru-sound";
 		rockchip,cpu = <&i2s0 &i2s2>;
 		rockchip,codec = <&max98357a &headsetcodec
-				  &codec &wacky_spi_audio>;
+				  &codec &wacky_spi_audio &cdn_dp>;
 	};
 };
 
+&cdn_dp {
+	status = "okay";
+	extcon = <&usbc_extcon0>, <&usbc_extcon1>;
+};
+
 /*
  * Set some suspend operating points to avoid OVP in suspend
  *