ARM: dts: stm32f429: add missing #reset-cells of rcc

This patch adds #reset-cells property to rcc node.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

arch/arm/boot/dts/stm32f429.dtsi

@@ -326,6 +326,7 @@ pins {
 		};
 
 		rcc: rcc@40023810 {
+			#reset-cells = <1>;
 			#clock-cells = <2>;
 			compatible = "st,stm32f42xx-rcc", "st,stm32-rcc";
 			reg = <0x40023800 0x400>;