arm64: dts: rockchip: Add soc-ctl-syscon to sdhci for rk3399

On rk3399 we'd like to be able to properly set corecfg registers in the
Arasan SDHCI component.  Specify the syscon to enable that.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

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

@@ -229,6 +229,7 @@
 		compatible = "rockchip,rk3399-sdhci-5.1", "arasan,sdhci-5.1";
 		reg = <0x0 0xfe330000 0x0 0x10000>;
 		interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
+		arasan,soc-ctl-syscon = <&grf>;
 		assigned-clocks = <&cru SCLK_EMMC>;
 		assigned-clock-rates = <200000000>;
 		clocks = <&cru SCLK_EMMC>, <&cru ACLK_EMMC>;