ARM: dts: stm32: Fix memory size from 8MB to 16MB on stm32f469-disco board

This patch fix memory size to support 16MB of external SDRAM.
Signed-off-by: Bruno Herrera <bruherrera@gmail.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32f469-disco.dts

@@ -58,7 +58,7 @@ chosen {
 	};
 
 	memory {
-		reg = <0x00000000 0x800000>;
+		reg = <0x00000000 0x1000000>;
 	};
 
 	aliases {