uboot-imx

fdt: Support for ISA busses

Support ISA busses in much the same way as Linux does. This allows for
ISA bus addresses to be translated, and only if CONFIG_OF_ISA_BUS is
selected in order to avoid including the code in builds which won't need
it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Simon Glass <sjg@chromium.org>