hw/virtio/Kconfig: Include vhost-user-scmi only on arm targets

The System Control and Management Interface is specific to arm
machines, so don't include this device in non-arm targets.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/virtio/Kconfig

@@ -109,4 +109,4 @@ config VHOST_USER_SND
 config VHOST_USER_SCMI
     bool
     default y
-    depends on VIRTIO && VHOST_USER
+    depends on VIRTIO && VHOST_USER && ARM