perf tools: Add support for guest/host-only profiling

perf tools: Add support for guest/host-only profiling

To restrict a counter to either host or guest mode this patch introduces
two new event modifiers: G and H.

With G the counter is configured in guest-only mode and with H in
host-only mode.

Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/n/tip-or5aj3rghy9ngyg882z6kln9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>