Leave the core usb devices (usb hub, tablet, mouse, keyboard)
enabled unconditionally. Make the other ones configurable.
Exceptions:
- bluetooth: not qdevified yet, has a vl.c dependency because
of that, thus disabling isn't as easy as not linking the
object file.
- smardcard: ccid-card-emulated depends on that one *and*
CONFIG_SMARTCARD_NSS. So it isn't a one-liner and comes
as separate patch because of that.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>