ARM: dts: da850: get rid of skeleton.dtsi

skeleton.dtsi is deprecated. Drop its usage in da850.dtsi
and move the nodes and properties included by it directly
to keep the dtb same.

The memory node has been changed to get rid of warnings
(see below). It contains the memory base address as that is
fixed for DA850 SoCs. But the size needs to be added by
bootloader or a board specific dts.

This gets rid of the following W=1 warnings:

arch/arm/boot/dts/da850-enbw-cmc.dtb: Warning (unit_address_vs_reg): /memory: node has a reg or ranges property, but no unit name
arch/arm/boot/dts/da850-evm.dtb: Warning (unit_address_vs_reg): /memory: node has a reg or ranges property, but no unit name
arch/arm/boot/dts/da850-lego-ev3.dtb: Warning (unit_address_vs_reg): /memory: node has a reg or ranges property, but no unit name

Reviewed-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>