vhost: split out vringh Kconfig

vringh is pulled in by caif and mic, but the other
vhost config does not need to be there.
In particular, it makes no sense to have vhost net/scsi/sock
under caif/mic.

Create a separate Kconfig file and put vringh bits there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/misc/mic/Kconfig

@@ -148,5 +148,5 @@ config VOP
 	  <http://software.intel.com/en-us/mic-developer>.
 
 if VOP
-source "drivers/vhost/Kconfig"
+source "drivers/vhost/Kconfig.vringh"
 endif

drivers/net/caif/Kconfig

@@ -52,5 +52,5 @@ config CAIF_VIRTIO
 	The caif driver for CAIF over Virtio.
 
 if CAIF_VIRTIO
-source "drivers/vhost/Kconfig"
+source "drivers/vhost/Kconfig.vringh"
 endif

drivers/vhost/Kconfig

@@ -33,12 +33,6 @@ config VHOST_VSOCK
 	To compile this driver as a module, choose M here: the module will be called
 	vhost_vsock.
 
-config VHOST_RING
-	tristate
-	---help---
-	  This option is selected by any driver which needs to access
-	  the host side of a virtio ring.
-
 config VHOST
 	tristate
 	---help---

drivers/vhost/Kconfig.vringh

+config VHOST_RING
+	tristate
+	---help---
+	  This option is selected by any driver which needs to access
+	  the host side of a virtio ring.