We are going to remove the bluetooth backend, so the USB bluetooth
dongle can not work anymore. It's a completely optional device, no
board depends on it, so let's simply remove it now.

Message-Id: <20191120091014.16883-3-thuth@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>