fdtdec: Allow using fdtdec_get_carveout() in loops

In order make it possible to use fdtdec_get_carveout() in loops, return
FDT_ERR_NOTFOUND when the passed-in index exceeds the number of phandles
present in the given property.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index af92e65..f2861eb 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1431,7 +1431,7 @@
 
 	if (len < (sizeof(phandle) * (index + 1))) {
 		debug("invalid phandle index\n");
-		return -FDT_ERR_BADPHANDLE;
+		return -FDT_ERR_NOTFOUND;
 	}
 
 	phandle = fdt32_to_cpu(prop[index]);