qapi: move inclusions of qemu-common.h from headers to .c files

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 3c4678d..2db0bf1 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -366,6 +366,7 @@
  *
  */
 
+#include "qemu-common.h"
 #include "qemu-objects.h"
 #include "qapi/qmp-core.h"
 #include "qapi/qapi-visit-core.h"