gitignore: Filter m4 files

Change-Id: I1ed0e5999a0b131091d78544d06a7be3c803a139
1 file changed
tree: d10063f9ec0899b7cdb913507dc54dfdc5ffdb88
  1. contrib/
  2. debian/
  3. openbsc/
  4. .gitignore
  5. .gitreview
  6. .mailmap