monitor: move include files to include/monitor/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/audio/audio.c b/audio/audio.c
index 1c77389..a0cc727 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -23,7 +23,7 @@
  */
 #include "hw/hw.h"
 #include "audio.h"
-#include "monitor.h"
+#include "monitor/monitor.h"
 #include "qemu-timer.h"
 #include "sysemu.h"