Makefile: always call date with LC_ALL=C set

Ensure that date is called only with LC_ALL=C locale set to make dates
locale neutral thus preventing lurking of non-ASCII characters into
U-Boot binary.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>

Changed LANG= into LC_ALL= as suggested by Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/Makefile b/Makefile
index 55bb964..9a436fe 100644
--- a/Makefile
+++ b/Makefile
@@ -385,8 +385,8 @@
 		@cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@
 
 $(TIMESTAMP_FILE):
-		@date +'#define U_BOOT_DATE "%b %d %C%y"' > $@
-		@date +'#define U_BOOT_TIME "%T"' >> $@
+		@LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"' > $@
+		@LC_ALL=C date +'#define U_BOOT_TIME "%T"' >> $@
 
 gdbtools:
 		$(MAKE) -C tools/gdb all || exit 1
@@ -3751,6 +3751,6 @@
 
 backup:
 	F=`basename $(TOPDIR)` ; cd .. ; \
-	gtar --force-local -zcvf `date "+$$F-%Y-%m-%d-%T.tar.gz"` $$F
+	gtar --force-local -zcvf `LC_ALL=C date "+$$F-%Y-%m-%d-%T.tar.gz"` $$F
 
 #########################################################################