arm64: KVM: Implement timer save/restore

Implement the timer save restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
index 5759f9f..f213e46 100644
--- a/arch/arm64/kvm/hyp/hyp.h
+++ b/arch/arm64/kvm/hyp/hyp.h
@@ -35,5 +35,8 @@
 void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
 void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
 
+void __timer_save_state(struct kvm_vcpu *vcpu);
+void __timer_restore_state(struct kvm_vcpu *vcpu);
+
 #endif /* __ARM64_KVM_HYP_H__ */