davinci: da850/omap-l138: Modify NOR partition info

On DA850/OMAP-L138, NOR flash partition was starting from offset
ZERO erasing the UBL and u-boot when the complete NOR is erased.
This patch moves the start of the partition to 512K, after the
bootloaders and u-boot env variables.

This patch also creates a new partition on NOR Flash to store
Linux kernel image.

Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>