Ignore files generated by cscope tool

Signed-off-by: Max <msuraev@sysmocom.de>
diff --git a/.gitignore b/.gitignore
index 6cc9aa5..a22fd4f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 Makefile.in
 Makefile
 .deps
+src/cscope*
 
 aclocal.m4
 autom4te.cache