powerpc/xive: Remove unused inline function xive_kexec_teardown_cpu()

commit e27e0a94 ("powerpc/xive: Remove xive_kexec_teardown_cpu()")
left behind this, remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200715025040.33952-1-yuehaibing@huawei.com

arch/powerpc/include/asm/xive.h

@@ -155,7 +155,6 @@ static inline void xive_smp_probe(void) { }
 static inline int  xive_smp_prepare_cpu(unsigned int cpu) { return -EINVAL; }
 static inline void xive_smp_setup_cpu(void) { }
 static inline void xive_smp_disable_cpu(void) { }
-static inline void xive_kexec_teardown_cpu(int secondary) { }
 static inline void xive_shutdown(void) { }
 static inline void xive_flush_interrupt(void) { }