Removed some nonused fdt functions and moved fdt_find_and_setprop out of libfdt

Removed:
	fdt_node_is_compatible
	fdt_find_node_by_type
	fdt_find_compatible_node

To ease merge of newer libfdt as we aren't using them anywhere at this time.

Also moved fdt_find_and_setprop out of libfdt into fdt_support.c for the same
reason.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>