perf tools: .gitignore += config.make config.make.autogen

These are local-configuration files and should be ignored.

LKML-Reference: <1276516847-25817-1-git-send-email-kirr@landau.phys.spbu.ru>
Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>