ppc4xx: Enable device tree support (fdt) on Kilauea per default

This patch enables the fdt support on the AMCC Kilauea eval board.
Additionally now EBC ranges fdt fixup is included to support NOR
FLASH mapping via the Linux physmap_of driver.

This Kilauea port now support booting arch/ppc and arch/powerpc
Linux kernels. The default environment "net_nfs" is for arch/ppc
and "net_nfs_fdt" is for arch/powerpc. In the long run, arch/ppc
support will be removed.

Signed-off-by: Stefan Roese <sr@denx.de>