ppc: Express dependencies of the 'prep' and '40p' machines with kconfig

Select the required devices in hw/ppc/Kconfig instead, so that
ppc-softmmu.mak only contains the user-selectable PREP switch.
Plug-in devices like NE2000_ISA are pulled in automatically by the
Kconfig build system now.

Cc: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 files changed