perf completion: Complete 'perf kvm'

Currently, there is no way to enumerate the subcommands under 'perf
kvm', so hardcode them.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Link: http://lkml.kernel.org/r/1386758056-24618-2-git-send-email-artagnon@gmail.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>