rockchip: dts: Enable SARADC for rk3368-sheep

Enable the SARADC for download key pressed detect.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/arch/arm/dts/rk3368-sheep.dts b/arch/arm/dts/rk3368-sheep.dts
index 7c190f7..27befad 100644
--- a/arch/arm/dts/rk3368-sheep.dts
+++ b/arch/arm/dts/rk3368-sheep.dts
@@ -260,6 +260,10 @@
 	};
 };
 
+&saradc {
+	status = "okay";
+};
+
 &tsadc {
 	status = "okay";
 	rockchip,hw-tshut-mode = <0>; /* CRU */