x86/kvm: hide KVM options from menuconfig when KVM is not compiled

Let KVM_WERROR depend on KVM, so it doesn't show in menuconfig alone.
Signed-off-by: NMatteo Croce <mcroce@microsoft.com>
Message-Id: <20201001112014.9561-1-mcroce@linux.microsoft.com>
Fixes: 4f337faf ("KVM: allow disabling -Werror")
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/Kconfig

@@ -66,6 +66,7 @@ config KVM_WERROR
 	default y if X86_64 && !KASAN
 	# We use the dependency on !COMPILE_TEST to not be enabled
 	# blindly in allmodconfig or allyesconfig configurations
+	depends on KVM
 	depends on (X86_64 && !KASAN) || !COMPILE_TEST
 	depends on EXPERT
 	help