libfdt: Remove #includes from fdt.h

At present fdt.h #includes stdint.h.  This makes some sense, because fdt.h
uses the standard fixed-width integer types.  However, this can make life
difficult when building in different environments which may not have a
stdint.h.  Therefore, this patch removes the #include from fdt.h, instead
requiring that users of fdt.h define the fixed-width integer types before
including fdt.h, either by themselves including stdint.h, or by any other
means.

tests/truncated_property.c

@@ -21,6 +21,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdint.h>
 
 #include <fdt.h>
 #include <libfdt.h>