add "tags" to .gitignore

Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

.gitignore

@@ -16,6 +16,7 @@
 #
 # Top-level generic files
 #
+tags
 vmlinux*
 System.map
 Module.symvers