x86: remove built-in vhost-net driver

This is now available as a kmod package (kmod-vhost-net).
Signed-off-by: NMathew McBride <matt@traverse.com.au>

target/linux/x86/generic/config-5.15

@@ -399,9 +399,6 @@ CONFIG_TREE_SRCU=y
 CONFIG_UCS2_STRING=y
 CONFIG_USB_STORAGE=y
 CONFIG_USER_RETURN_NOTIFIER=y
-CONFIG_VHOST=y
-CONFIG_VHOST_IOTLB=y
-CONFIG_VHOST_NET=y
 CONFIG_VIRTIO=y
 CONFIG_VIRTIO_BALLOON=y
 CONFIG_VIRTIO_BLK=y