fdt: Move MULTI_DTB_FIT handling out of fdtdec_setup()

This logic is a bit convoluted for one function. Move the mulit-FIT part
into its own function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
1 file changed