mtd: onenand: omap2: Fix errors in style

Correct mispelling, spacing, and coding style flaws caught by
checkpatch.pl script in the Omap2 Onenand driver .

Signed-off-by: Amir Mahdi Ghorbanian <indigoomega021@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>