KVM: PPC: Move KVM_PPC_PVINFO_FLAGS_EV_IDLE definition next to its structure

The KVM_PPC_PVINFO_FLAGS_EV_IDLE macro defines a bit for use in the flags
field of struct kvm_ppc_pvinfo.  However, changes since that was introduced
have moved it away from that structure definition, which is confusing.

Move it back next to the structure it belongs with.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>