uboot-imx

NAND boot: change NAND loader's relocate SP to CONFIG param

So that we can set the NAND loader's relocate stack pointer
to the value other than the relocate address + 0x10000.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>