ARM: OMAP3_LOGIC: Update MTD Partition Table

The previous partition table did not support a separate device tree
and the kernel size was limited to 4MB.  This update shows the
location of the device tree (labeled as spl-os) for those who
want to use Falcon Mode or use U-Boot to store the Flattened
Device Tree (FDT) to NAND without appending it to the kernel.

This also grows the kernel to 6MB since 4MB was becomming tight

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>