KVM: PPC: booke: Mark three local functions "static"

Tag a few functions that are local and don't have a previous prototype
as "static".

No functional change intended.

Reported-by: kernel test robot <[e-mail]>
Link: https://lore.kernel.org/oe-kbuild-all/[e-mail]
Signed-off-by: Sean Christopherson <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://msgid.link/[e-mail]

arch/powerpc/kvm/booke.c

···
 	spin_unlock_irqrestore(&vcpu->arch.wdt_lock, flags);
 }
 
-void kvmppc_watchdog_func(struct timer_list *t)
+static void kvmppc_watchdog_func(struct timer_list *t)
 {
 	struct kvm_vcpu *vcpu = from_timer(vcpu, t, arch.wdt_timer);
 	u32 tsr, new_tsr;
···
 	dbg_reg->dbcr0 |= DBCR0_IDM;
 	return 0;
 }
-void kvm_guest_protect_msr(struct kvm_vcpu *vcpu, ulong prot_bitmap, bool set)
+static void kvm_guest_protect_msr(struct kvm_vcpu *vcpu, ulong prot_bitmap,
+				  bool set)
 {
 	/* XXX: Add similar MSR protection for BookE-PR */
 #ifdef CONFIG_KVM_BOOKE_HV

arch/powerpc/kvm/e500mc.c

···
 	kvmppc_booke_vcpu_put(vcpu);
 }
 
-int kvmppc_e500mc_check_processor_compat(void)
+static int kvmppc_e500mc_check_processor_compat(void)
 {
 	int r;