gitignore: Update .gitignore to include mboxctl

Update .gitignore to include the new output file mboxctl.

While we're here add cscope.out since this is often in the project repo.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Change-Id: I0dd2d8b23bf28a68a740fab7c3fd8c82544975ae
diff --git a/.gitignore b/.gitignore
index 75b5f88..dcb9f42 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,4 +48,5 @@
 .deps
 arm-openbmc-linux-gnueabi-libtool
 mboxd
-
+mboxctl
+cscope.out