scripts/dtc: Update to upstream version v1.4.5-3-gb1a60033c110

This adds the following commits from upstream:

b1a6003 tests: Add a test for overlays syntactic sugar
737b2df overlay: Add syntactic sugar version of overlays
497432f checks: Use proper format modifier for size_t
22a65c5 dtc: Bump version to v1.4.5
c575d80 Add fdtoverlay to .gitignore
b6a6f94 fdtoverlay: Sanity check blob size
8c1eb15 pylibfdt: Use Python2 explicitly
ee3d26f checks: add interrupts property check
c1e7738 checks: add gpio binding properties check
b3bbac0 checks: add phandle with arg property checks

[ sync with Linux commit: 4201d057ea91c3d6efd2db65219bc91fae413bc2 ]

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/dtc/dtc-parser.y

@@ -182,10 +182,19 @@ devicetree:
 		{
 			struct node *target = get_node_by_ref($1, $2);
 
-			if (target)
+			if (target) {
 				merge_nodes(target, $3);
-			else
-				ERROR(&@2, "Label or path %s not found", $2);
+			} else {
+				/*
+				 * We rely on the rule being always:
+				 *   versioninfo plugindecl memreserves devicetree
+				 * so $-1 is what we want (plugindecl)
+				 */
+				if ($<flags>-1 & DTSF_PLUGIN)
+					add_orphan_node($1, $3, $2);
+				else
+					ERROR(&@2, "Label or path %s not found", $2);
+			}
 			$$ = $1;
 		}
 	| devicetree DT_DEL_NODE DT_REF ';'
@@ -200,6 +209,11 @@ devicetree:
 
 			$$ = $1;
 		}
+	| /* empty */
+		{
+			/* build empty node */
+			$$ = name_node(build_node(NULL, NULL), "");
+		}
 	;
 
 nodedef: