dtc: Allow multiple labels on nodes and properties

At present, both the grammar and our internal data structures mean
that there can be only one label on a node or property.  This is a
fairly arbitrary constraint, given that any number of value labels can
appear at the same point, and that in C you can have any number of
labels on the same statement.

This is pretty much a non-issue now, but it may become important with
some of the extensions that Grant and I have in mind.  It's not that
hard to change, so this patch does so, allowing an arbitrary number of
labels on any given node or property.  As usual a testcase is added
too.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/treesource.c b/treesource.c
index 331c22c..c09aafa 100644
--- a/treesource.c
+++ b/treesource.c
@@ -235,10 +235,11 @@
 {
 	struct property *prop;
 	struct node *child;
+	struct label *l;
 
 	write_prefix(f, level);
-	if (tree->label)
-		fprintf(f, "%s: ", tree->label);
+	for_each_label(tree->labels, l)
+		fprintf(f, "%s: ", l->label);
 	if (tree->name && (*tree->name))
 		fprintf(f, "%s {\n", tree->name);
 	else
@@ -246,8 +247,8 @@
 
 	for_each_property(tree, prop) {
 		write_prefix(f, level+1);
-		if (prop->label)
-			fprintf(f, "%s: ", prop->label);
+		for_each_label(prop->labels, l)
+			fprintf(f, "%s: ", l->label);
 		fprintf(f, "%s", prop->name);
 		write_propval(f, prop);
 	}
@@ -267,8 +268,10 @@
 	fprintf(f, "/dts-v1/;\n\n");
 
 	for (re = bi->reservelist; re; re = re->next) {
-		if (re->label)
-			fprintf(f, "%s: ", re->label);
+		struct label *l;
+
+		for_each_label(re->labels, l)
+			fprintf(f, "%s: ", l->label);
 		fprintf(f, "/memreserve/\t0x%016llx 0x%016llx;\n",
 			(unsigned long long)re->re.address,
 			(unsigned long long)re->re.size);