This patch fixes the omap2 nand driver code that allows
reading of partition data from board info.

The parse_mtd_partitions() function no longer returns a
negative error in case cmdline is not passed.
See commit: b0d06afbSigned-off-by: Nishant Kamat <nskamat@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>