ARM: omap3: Add missing memory node in SOM-LV

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

commit ("766a1fe7 ARM: omap3: Add missing memory node") had
fixes for Torpedo and Overo boards, but this SOM-LV was missed.

This should help prevent the DTC warning:
"Node /memory has a reg or ranges property, but no unit name"

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>