dtc: backport patch to fix build with GCC v10 on DTC v1.4.5

This commit backports a patch to fix the following build issue with
the GCC v10:
    dtc-parser.tab.c:1069: multiple definition of `yylloc'

Signed-off-by: Arturo Buzarra <arturo.buzarra@digi.com>

meta-digi-arm/recipes-kernel/dtc/dtc/0001-Remove-redundant-YYLOC-global-declaration.patch

@@ -0,0 +1,49 @@
+From: Dirk Mueller <dmueller@suse.com>
+Date: Tue, 14 Jan 2020 18:53:41 +0100
+Subject: [PATCH] Remove redundant YYLOC global declaration
+
+gcc 10 will default to -fno-common, which causes this error at link
+time:
+
+  (.text+0x0): multiple definition of `yylloc'; dtc-lexer.lex.o (symbol from plugin):(.text+0x0): first defined here
+
+This is because both dtc-lexer as well as dtc-parser define the same
+global symbol yyloc. Before with -fcommon those were merged into one
+defintion. The proper solution would be to to mark this as "extern",
+however that leads to:
+
+  dtc-lexer.l:26:16: error: redundant redeclaration of 'yylloc' [-Werror=redundant-decls]
+   26 | extern YYLTYPE yylloc;
+      |                ^~~~~~
+In file included from dtc-lexer.l:24:
+dtc-parser.tab.h:127:16: note: previous declaration of 'yylloc' was here
+  127 | extern YYLTYPE yylloc;
+      |                ^~~~~~
+cc1: all warnings being treated as errors
+
+which means the declaration is completely redundant and can just be
+dropped.
+
+Signed-off-by: Dirk Mueller <dmueller@suse.com>
+Message-Id: <20200114175341.2994-1-dmueller@suse.com>
+Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
+---
+ dtc-lexer.l | 1 -
+ 1 file changed, 1 deletion(-)
+
+diff --git a/dtc-lexer.l b/dtc-lexer.l
+index 5c6c3fd..b3b7270 100644
+--- a/dtc-lexer.l
++++ b/dtc-lexer.l
+@@ -21,11 +21,10 @@ LINECOMMENT	"//".*\n
+ %{
+ #include "dtc.h"
+ #include "srcpos.h"
+ #include "dtc-parser.tab.h"
+
+-YYLTYPE yylloc;
+ extern bool treesource_error;
+
+ /* CAUTION: this will stop working if we ever use yyless() or yyunput() */
+ #define	YY_USER_ACTION \
+ 	{ \

meta-digi-arm/recipes-kernel/dtc/dtc_1.4.5.bb

@@ -7,6 +7,10 @@ LIC_FILES_CHKSUM = "file://GPL;md5=94d55d512a9ba36caa9b7df079bae19f \
 
 SRCREV = "22a65c5331c22979d416738eb756b9541672e00d"
 
+SRC_URI_append = " \
+    file://0001-Remove-redundant-YYLOC-global-declaration.patch \
+"
+
 S = "${WORKDIR}/git"
 
 BBCLASSEXTEND = "native nativesdk"