uboot-imx

arm/km: use kw_sdram_size_adjust to adjust SDRAM size

Some boards may differ only in the SDRAM size. This function allows to
fix the size accordingly and we can use the same u-boot binary for both
boards.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>