[PATCH] ppc64: tidy up vio devices fake parent

Currently we dynamically allocate the fake parent device for all devices on
the vio bus.  This patch statically allocates it.  This also allows us to
reuse it for the iSeries "generic" vio device (that is used for passing to
dma routines when communicating with the hypervisor without a device
involved).  Also unexport vio_bus_type as it is never used in modules.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>