kvm: Provide sigbus services arch-independently

Provide arch-independent kvm_on_sigbus* stubs to remove the #ifdef'ery
from cpus.c. This patch also fixes --disable-kvm build by providing the
missing kvm_on_sigbus_vcpu kvm-stub.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/kvm-all.c b/kvm-all.c
index 55f6ac3..a83aff2 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1366,3 +1366,13 @@
     return -ENOSYS;
 #endif
 }
+
+int kvm_on_sigbus_vcpu(CPUState *env, int code, void *addr)
+{
+    return kvm_arch_on_sigbus_vcpu(env, code, addr);
+}
+
+int kvm_on_sigbus(int code, void *addr)
+{
+    return kvm_arch_on_sigbus(code, addr);
+}