nand: mxc: Use appropriate page number in syndrome functions

The syndrome functions should use the page number passed as argument instead of
the page number saved upon NAND_CMD_READ0.

This does not make any difference if the NAND_NO_AUTOINCR option is set, but
otherwise this fixes accesses to the wrong pages.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Acked-by: Scott Wood <scottwood@freescale.com>