KVM: PPC: bookehv: Add EPCR support in mtspr/mfspr emulation

Add EPCR support in booke mtspr/mfspr emulation. EPCR register is defined only
for 64-bit and HV categories, we will expose it at this point only to 64-bit
virtual processors running on 64-bit HV hosts.
Define a reusable setter function for vcpu's EPCR.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[agraf: move HV dependency in the code]
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/booke.h b/arch/powerpc/kvm/booke.h
index ba61974..e9b88e4 100644
--- a/arch/powerpc/kvm/booke.h
+++ b/arch/powerpc/kvm/booke.h
@@ -69,6 +69,7 @@
 void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr);
 void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr);
 
+void kvmppc_set_epcr(struct kvm_vcpu *vcpu, u32 new_epcr);
 void kvmppc_set_tcr(struct kvm_vcpu *vcpu, u32 new_tcr);
 void kvmppc_set_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits);
 void kvmppc_clr_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits);