8baf73adf6 (qdev/isa: convert fdc)
breaks MIPS Malta:
Tried to create isa device isa-fdc with no isa bus present
Fix this by creating an isa bus for piix4.
This change also requires some more qdev related changes
(similar changes were applied to pc.c) and allows
cleaning of piix3/piix4 code.
Thanks to Gerd Hoffmann for his hints.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
