ARM: dts: stm32: add FMC2 EBI support for stm32mp157c

This patch adds FMC2 External Bus Interface support on stm32mp157c.

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32mp157c-ev1.dts b/arch/arm/dts/stm32mp157c-ev1.dts
index b190565..46f81ce 100644
--- a/arch/arm/dts/stm32mp157c-ev1.dts
+++ b/arch/arm/dts/stm32mp157c-ev1.dts
@@ -157,14 +157,16 @@
 	pinctrl-0 = <&fmc_pins_a>;
 	pinctrl-1 = <&fmc_sleep_pins_a>;
 	status = "okay";
-	#address-cells = <1>;
-	#size-cells = <0>;
+
+	nand-controller@4,0 {
+		status = "okay";
 
-	nand@0 {
-		reg = <0>;
-		nand-on-flash-bbt;
-		#address-cells = <1>;
-		#size-cells = <1>;
+		nand@0 {
+			reg = <0>;
+			nand-on-flash-bbt;
+			#address-cells = <1>;
+			#size-cells = <1>;
+		};
 	};
 };