[MTD] [NAND] corrected MPC8313 NAND fixes

Fix a race condition in fsl_elbc_run_command
Fix incorrect usage of clearbits32 that bashed option register
Remove work around for bashed register

Signed-off-by: Mike Hench <mhench@elutions.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>