KVM: x86: remove unused declaration of kvm_write_tsc()

kvm_write_tsc() was renamed and made static since commit 0c899c25
("KVM: x86: do not attempt TSC synchronization on guest writes"). Remove
its unused declaration.
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Message-Id: <20210326070334.12310-1-dongli.zhang@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.h

@@ -250,7 +250,6 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu)
 void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs);
 void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);
 
-void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr);
 u64 get_kvmclock_ns(struct kvm *kvm);
 
 int kvm_read_guest_virt(struct kvm_vcpu *vcpu,