hw/isa: fix ISA_SUPERIO dependencies

hw/isa: fix ISA_SUPERIO dependencies

ISA_SUPERIO does not provide an ISA bus, so it should not select the symbol:
instead it requires one.  Among its users, VT82C686 is the only one that
is a PCI-ISA bridge and does not already select ISA_BUS.

Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Bernhard Beschow <shentey@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240213155005.109954-5-pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>