scripts/dtc: Update to upstream version v1.4.6-21-g84e414b0b5bc

This adds the following commits from upstream:

84e414b0b5bc tests: Add a test case for the omit-if-no-ref keyword
4038fd90056e dtc: add ability to make nodes conditional on them being referenced
e1f139ea4900 checks: drop warning for missing PCI bridge bus-range
f4eba68d89ee checks: Print duplicate node name instead of parent name
46df1fb1b211 .travis.yml: Run valgrind checks via Travis
14a3002a1aee tests: Update valgrind suppressions for sw_tree1
02c5fe9debc0 tests: Remove valgrind error from tests/get_path
df536831d02c checks: add graph binding checks
2347c96edcbe checks: add a check for duplicate unit-addresses of child nodes
8f1b35f88395 Correct overlay syntactic sugar for generating target-path fragments
afbddcd418fb Suppress warnings on overlay fragments
119e27300359 Improve tests for dtc overlay generation

Signed-off-by: Rob Herring <robh@kernel.org>

scripts/dtc/livetree.c

@@ -134,6 +134,20 @@ struct node *name_node(struct node *node, char *name)
 	return node;
 }
 
+struct node *omit_node_if_unused(struct node *node)
+{
+	node->omit_if_unused = 1;
+
+	return node;
+}
+
+struct node *reference_node(struct node *node)
+{
+	node->is_referenced = 1;
+
+	return node;
+}
+
 struct node *merge_nodes(struct node *old_node, struct node *new_node)
 {
 	struct property *new_prop, *old_prop;
@@ -224,10 +238,16 @@ struct node * add_orphan_node(struct node *dt, struct node *new_node, char *ref)
 	struct data d = empty_data;
 	char *name;
 
-	d = data_add_marker(d, REF_PHANDLE, ref);
-	d = data_append_integer(d, 0xffffffff, 32);
+	if (ref[0] == '/') {
+		d = data_append_data(d, ref, strlen(ref) + 1);
 
-	p = build_property("target", d);
+		p = build_property("target-path", d);
+	} else {
+		d = data_add_marker(d, REF_PHANDLE, ref);
+		d = data_append_integer(d, 0xffffffff, 32);
+
+		p = build_property("target", d);
+	}
 
 	xasprintf(&name, "fragment@%u",
 			next_orphan_fragment++);