qapi-types.h: Don't include qemu-common.h

Needed to prevent build breakage when CPUState becomes a child of
DeviceState.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
[ehabkost: include <stdbool.h> too]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
