uboot-imx

km/km82xx: remove CONFIG_SYS_RAMBOOT

This define is never set in our setup, so we can remove it safely. The
former code causes cppcheck to complain about:
[board/keymile/km82xx/km82xx.c:311]: (error) Uninitialized variable:
psize

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Wolfgang Denk <wd@denx.de>
Reviewed-by: York Sun <yorksun@freescale.com>