Fix OneNAND ipl to read CONFIG_SYS_MONITOR_LEN

Currently OneNAND initial program loader (ipl) reads only block 0 ie 128KB.
However, u-boot image for apollon board is 195KB making the board
unbootable with OneNAND.

Fix ipl to read CONFIG_SYS_MONITOR_LEN.
CONFIG_SYS_MONITOR_LEN macro holds the U-Boot image size.

Signed-off-by: Rohit Hagargundgi <h.rohit@samsung.com>
Signed-off-by: Gangheyamoorthy <moorthy.apg@samsung.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>