dm: Return actual bools in dm_fdt_pre_reloc

Documentation says that we're returning true/false, not 1/0 so adapt
the function to return actual booleans.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>

include/dm/util.h

@@ -72,6 +72,6 @@ static inline void dm_dump_devres(void)
  *
  * Returns true if node is needed in SPL/TL, false otherwise.
  */
-int dm_fdt_pre_reloc(const void *blob, int offset);
+bool dm_fdt_pre_reloc(const void *blob, int offset);
 
 #endif