target-ppc: Remove CONFIG_PSERIES dependency in kvm.c

target-ppc: Remove CONFIG_PSERIES dependency in kvm.c

target-ppc/kvm.c has an #ifdef on CONFIG_PSERIES, for the handling of
KVM exits due to a PAPR hypercall from the guest.  However, since commit
e4c8b28cde12d01ada8fe869567dc5717a2dfcb7 "ppc: express FDT dependency of
pSeries and e500 boards via default-configs/", this hasn't worked properly.
That patch altered the configuration setup so that although CONFIG_PSERIES
is visible from the Makefiles, it is not visible from C files.  This broke
the pseries machine when KVM is in use.

This patch makes a quick and dirty fix, by removing the CONFIG_PSERIES
dependency, replacing it with TARGET_PPC64 (since removing it entirely
leads to type mismatch errors).  Technically this breaks the build when
configured with --disable-fdt, since that disables CONFIG_PSERIES on
TARGET_PPC64.  However, it turns out the build was already broken in that
case, so this fixes pseries kvm without breaking anything extra.  I'm
looking into how to fix that build breakage, but I don't think that need
delay applying this patch.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>