MIPS: kvm: Declare prototype for kvm_init_loongson_ipi

Declear prototype for kvm_init_loongson_ipi in interrupt.h.

Fix warning:
arch/mips/kvm/loongson_ipi.c:190:6: warning: no previous prototype for ‘kvm_init_loongson_ipi’ [-Wmissing-prototypes]
  190 | void kvm_init_loongson_ipi(struct kvm *kvm)
      |      ^~~~~~~~~~~~~~~~~~~~~

Fixes: f21db309 ("KVM: MIPS: Add Loongson-3 Virtual IPI interrupt support")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/kvm/interrupt.h

@@ -37,3 +37,7 @@ u32 kvm_irq_to_priority(u32 irq);
 int kvm_mips_pending_timer(struct kvm_vcpu *vcpu);
 
 void kvm_mips_deliver_interrupts(struct kvm_vcpu *vcpu, u32 cause);
+
+#ifdef CONFIG_CPU_LOONGSON64
+extern void kvm_init_loongson_ipi(struct kvm *kvm);
+#endif

arch/mips/kvm/loongson_ipi.c

@@ -10,6 +10,8 @@
 
 #include <linux/kvm_host.h>
 
+#include "interrupt.h"
+
 #define IPI_BASE            0x3ff01000ULL
 
 #define CORE0_STATUS_OFF       0x000

arch/mips/kvm/mips.c

@@ -135,8 +135,6 @@ void kvm_arch_hardware_disable(void)
 	kvm_mips_callbacks->hardware_disable();
 }
 
-extern void kvm_init_loongson_ipi(struct kvm *kvm);
-
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	switch (type) {