scripts/dtc: Update to upstream version v1.4.6-9-gaadd0b65c987

This adds the following commits from upstream:

aadd0b65c987 checks: centralize printing of property names in failure messages
88960e398907 checks: centralize printing of node path in check_msg
f1879e1a50eb Add limited read-only support for older (V2 and V3) device tree to libfdt.
37dea76e9700 srcpos: drop special handling of tab
65893da4aee0 libfdt: overlay: Add missing license
962a45ca034d Avoid installing pylibfdt when dependencies are missing
cd6ea1b2bea6 Makefile: Split INSTALL out into INSTALL_{PROGRAM,LIB,DATA,SCRIPT}
51b3a16338df Makefile.tests: Add LIBDL make(1) variable for portability sake
333d533a8f4d Attempt to auto-detect stat(1) being used if not given proper invocation
e54388015af1 dtc: Bump version to v1.4.6
a1fe86f380cb fdtoverlay: Switch from using alloca to malloc
c8d5472de3ff tests: Improve compatibility with other platforms
c81d389a10cc checks: add chosen node checks
e671852042a7 checks: add aliases node checks
d0c44ebe3f42 checks: check for #{size,address}-cells without child nodes
18a3d84bb802 checks: add string list check for *-names properties
8fe94fd6f19f checks: add string list check
6c5730819604 checks: add a string check for 'label' property
a384191eba09 checks: fix sound-dai phandle with arg property check
b260c4f610c0 Fix ambiguous grammar for devicetree rule
fe667e382bac tests: Add some basic tests for the pci_bridge checks
7975f6422260 Fix widespread incorrect use of strneq(), replace with new strprefixeq()
fca296445eab Add strstarts() helper function
cc392f089007 tests: Check non-matching cases for fdt_node_check_compatible()
bba26a5291c8 livetree: avoid assertion of orphan phandles with overlays
c8f8194d76cc implement strnlen for systems that need it
c8b38f65fdec libfdt: Remove leading underscores from identifiers
3b62fdaebfe5 Remove leading underscores from identifiers
2d45d1c5c65e Replace FDT_VERSION() with stringify()
2e6fe5a107b5 Fix some errors in comments
b0ae9e4b0ceb tests: Correct warning in sw_tree1.c

Commit c8b38f65fdec upstream ("libfdt: Remove leading underscores from
identifiers") changed the multiple inclusion define protection, so the
kernel's libfdt_env.h needs the corresponding update.

Signed-off-by: Rob Herring <robh@kernel.org>
[ Linux commit: 9130ba884640328bb78aaa4840e5ddf06ccafb1c ]
[erosca: - Fixup conflicts in include/linux/libfdt_env.h caused by v2018.03-rc4
           commit b08c8c487083 ("libfdt: move headers to <linux/libfdt.h>
	   and <linux/libfdt_env.h>")
	 - Fix build errors in lib/libfdt/fdt_ro.c, tools/libfdt/fdt_rw.c by:
	   - s/_fdt_mem_rsv/fdt_mem_rsv_/
	   - s/_fdt_offset_ptr/fdt_offset_ptr_/
	   - s/_fdt_check_node_offset/fdt_check_node_offset_/
	   - s/_fdt_check_prop_offset/fdt_check_prop_offset_/
	   - s/_fdt_find_add_string/fdt_find_add_string_/]
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/scripts/dtc/dtc-parser.y b/scripts/dtc/dtc-parser.y
index affc81a..44af170 100644
--- a/scripts/dtc/dtc-parser.y
+++ b/scripts/dtc/dtc-parser.y
@@ -166,7 +166,17 @@
 		{
 			$$ = merge_nodes($1, $3);
 		}
-
+	| DT_REF nodedef
+		{
+			/*
+			 * We rely on the rule being always:
+			 *   versioninfo plugindecl memreserves devicetree
+			 * so $-1 is what we want (plugindecl)
+			 */
+			if (!($<flags>-1 & DTSF_PLUGIN))
+				ERROR(&@2, "Label or path %s not found", $1);
+			$$ = add_orphan_node(name_node(build_node(NULL, NULL), ""), $2, $1);
+		}
 	| devicetree DT_LABEL DT_REF nodedef
 		{
 			struct node *target = get_node_by_ref($1, $3);
@@ -209,11 +219,6 @@
 
 			$$ = $1;
 		}
-	| /* empty */
-		{
-			/* build empty node */
-			$$ = name_node(build_node(NULL, NULL), "");
-		}
 	;
 
 nodedef: