x86: KVM guest: merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST

The distinction between CONFIG_KVM_CLOCK and CONFIG_KVM_GUEST is
not so clear anymore, as demonstrated by recent bugs caused by poor
handling of on/off combinations of these options.

Merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST.

Reported-By: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kernel/kvm.c

@@ -397,9 +397,7 @@ void kvm_disable_steal_time(void)
 #ifdef CONFIG_SMP
 static void __init kvm_smp_prepare_boot_cpu(void)
 {
-#ifdef CONFIG_KVM_CLOCK
 	WARN_ON(kvm_register_clock("primary cpu clock"));
-#endif
 	kvm_guest_cpu_init();
 	native_smp_prepare_boot_cpu();
 }