KVM: x86: add back X86_LOCAL_APIC dependency

Enabling KVM now causes a build failure on x86-32 if X86_LOCAL_APIC
is disabled:

arch/x86/kvm/svm/svm.c: In function 'svm_emergency_disable_virtualization_cpu':
arch/x86/kvm/svm/svm.c:597:9: error: 'kvm_rebooting' undeclared (first use in this function); did you mean 'kvm_irq_routing'?
  597 |         kvm_rebooting = true;
      |         ^~~~~~~~~~~~~
      |         kvm_irq_routing
arch/x86/kvm/svm/svm.c:597:9: note: each undeclared identifier is reported only once for each function it appears in
make[6]: *** [scripts/Makefile.build:221: arch/x86/kvm/svm/svm.o] Error 1
In file included from include/linux/rculist.h:11,
                 from include/linux/hashtable.h:14,
                 from arch/x86/kvm/svm/avic.c:18:
arch/x86/kvm/svm/avic.c: In function 'avic_pi_update_irte':
arch/x86/kvm/svm/avic.c:909:38: error: 'struct kvm' has no member named 'irq_routing'
  909 |         irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
      |                                      ^~
include/linux/rcupdate.h:538:17: note: in definition of macro '__rcu_dereference_check'
  538 |         typeof(*p) *local = (typeof(*p) *__force)READ_ONCE(p); \

Move the dependency to the same place as before.

Fixes: ea4290d ("KVM: x86: leave kvm.ko out of the build if no vendor module is requested")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410060426.e9Xsnkvi-lkp@intel.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sean Christopherson <seanjc@google.com>
[sean: add Cc to stable, tweak shortlog scope]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241118172002.1633824-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: arndb

arch/x86/kvm/Kconfig

@@ -19,7 +19,6 @@ if VIRTUALIZATION
 
 config KVM_X86
 	def_tristate KVM if KVM_INTEL || KVM_AMD
-	depends on X86_LOCAL_APIC
 	select KVM_COMMON
 	select KVM_GENERIC_MMU_NOTIFIER
 	select KVM_ELIDE_TLB_FLUSH_IF_YOUNG
@@ -51,6 +50,7 @@ config KVM_X86
 
 config KVM
 	tristate "Kernel-based Virtual Machine (KVM) support"
+	depends on X86_LOCAL_APIC
 	help
 	  Support hosting fully virtualized guest machines using hardware
 	  virtualization extensions.  You will need a fairly recent