nand/fsl_elbc: shrink SPL a bit by converting out_be32() to __raw_writel()

This is needed to make room for a bugfix on p1_p2_rdb_pc.  A sync is used
before the final write to LSOR that initiates the transaction, to ensure
all the other set up has been completed.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>