powerpc/mpc85xx: Move LAW_EN define outside of config

LAW_EN is only defined if CONFIG_SYS_CCSRBAR_DEFAULT is not equal to
CONFIG_SYS_CCSRBAR_PHYS. in SPL framework CCSRBAR is not relocated hence
both are same. This cause compilation error.

So LAW_EN define outside of configs

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>