KVM: Add reset support for in kernel PIT

Separate the reset part and prepare for reset support.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

arch/x86/kvm/i8254.h

@@ -58,5 +58,6 @@ void kvm_pit_timer_intr_post(struct kvm_vcpu *vcpu, int vec);
 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val);
 struct kvm_pit *kvm_create_pit(struct kvm *kvm);
 void kvm_free_pit(struct kvm *kvm);
+void kvm_pit_reset(struct kvm_pit *pit);
 
 #endif