ARM: omap3: Add missing memory node in overo and torpedo boards

The skeleton.dtsi file was removed in ARM64 for different reasons as
explained in commit ("3ebee5a2 arm64: dts: kill skeleton.dtsi").

These also applies to ARM and it will also allow to get rid of the
following DTC warnings in the future:

"Node /memory has a reg or ranges property, but no unit name"

But these boards don't have a memory node defined, so removing the
skeleton.dtsi inclusion from omap3.dtsi will cause a change in the
compiled DTB. Add a dummy memory node so the compiled DTB doesn't
change if the skeleton.dtsi is removed from omap3.dtsi.

Eventually the correct starting addresses and sizes should be used
but I didn't find that information.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/boot/dts/logicpd-torpedo-som.dtsi

@@ -13,6 +13,11 @@
 		};
 	};
 
+	memory {
+		device_type = "memory";
+		reg = <0 0>;
+	};
+
 	leds {
 		compatible = "gpio-leds";
 		user0 {

arch/arm/boot/dts/omap3-overo-base.dtsi

@@ -11,6 +11,12 @@
  */
 
 / {
+
+	memory {
+		device_type = "memory";
+		reg = <0 0>;
+	};
+
 	pwmleds {
 		compatible = "pwm-leds";