Don't include lib20 files in xrefs

The vboot 2.0 stuff is deprecated, so let's not index that when
building cross-references (cscope.files and TAGS).

BUG=none
BRANCH=ToT
TEST=manual

make xrefs

Change-Id: If3a9c42f869308acd929e32d5290e3354f5c3555
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/244751
Reviewed-by: Randall Spangler <rspangler@chromium.org>
diff --git a/Makefile b/Makefile
index 69ab492..3a2f836 100644
--- a/Makefile
+++ b/Makefile
@@ -1378,9 +1378,11 @@
 # paths inside and outside the chroot are different.
 SRCDIRPAT=$(subst /,\/,${SRCDIR}/)
 
+# Note: vboot 2.0 is deprecated, so don't index those files
 ${BUILD}/cscope.files: test_setup
 	${Q}rm -f $@
 	${Q}cat ${ALL_DEPS} | tr -d ':\\' | tr ' ' '\012' | \
+		grep -v /lib20/ | \
 		sed -e "s/${SRCDIRPAT}//" | \
 		egrep '\.[chS]$$' | sort | uniq > $@