KVM: PPC: Book3S PR: Add emulation for trechkpt.

This patch adds host emulation when guest PR KVM executes "trechkpt.",
which is a privileged instruction and will trap into host.

We firstly copy vcpu ongoing content into vcpu tm checkpoint
content, then perform kvmppc_restore_tm_pr() to do trechkpt.
with updated vcpu tm checkpoint values.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/kvm/book3s_pr.c

@@ -299,7 +299,7 @@ out:
 }
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-static inline void kvmppc_save_tm_sprs(struct kvm_vcpu *vcpu)
+void kvmppc_save_tm_sprs(struct kvm_vcpu *vcpu)
 {
 	tm_enable();
 	vcpu->arch.tfhar = mfspr(SPRN_TFHAR);