arm64: dts: rockchip: Fix mic-in-differential usage on rk3568-evb1-v10

The 'mic-in-differential' DT property supported by the RK809/RK817 audio
codec driver is actually valid if prefixed with 'rockchip,':

  DTC_CHK arch/arm64/boot/dts/rockchip/rk3568-evb1-v10.dtb

  rk3568-evb1-v10.dtb: pmic@20: codec: 'mic-in-differential' does not match any of the regexes: 'pinctrl-[0-9]+'
	from schema $id: http://devicetree.org/schemas/mfd/rockchip,rk809.yaml#

Make use of the correct property name.

Fixes: 3e4c629c ("arm64: dts: rockchip: enable rk809 audio codec on the rk3568 evb1-v10")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://lore.kernel.org/r/20240622-rk809-fixes-v2-5-c0db420d3639@collabora.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3568-evb1-v10.dts

@@ -475,7 +475,7 @@ regulator-state-mem {
 		};
 
 		codec {
-			mic-in-differential;
+			rockchip,mic-in-differential;
 		};
 	};
 };