ARM: dts: OMAP3: Add support for OMAP3430 SDP board

Adds basic device-tree support for OMAP3430 SDP board which has 256MB
of RAM, 128MB ONENAND flash, 256MB NAND flash and uses the TWL4030
power management IC.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>