build: Ignore buildinfo file

During deb package build, a .buildinfo file is created at build-root.
Add this to .gitignore.

Type: make

Signed-off-by: Renato Botelho do Couto <renato@netgate.com>
Change-Id: Id86c21e22aa2b9e4b559cfc0bc662de835fa1621
diff --git a/.gitignore b/.gitignore
index 4fb7ecc..4b7ed4f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@
 /build-root/path_setup
 /build-root/deb/debian/vpp-plugins/
 /build-root/deb/.pybuild/
+/build-root/*.buildinfo
 /build-root/*.deb
 /build-root/*.rpm
 /build-root/*.tar.xz