vhost: enable virtio control channel Rx mode
vhost: enable virtio control channel Rx mode

VIRTIO_NET_F_CTRL_RX is dependant on VIRTIO_NET_F_CTRL_VQ.
Observed that virtio-net driver in guest would crash with only CTRL_RX enabled.

In virtnet_send_command:

	/* Caller should know better */
	BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
		(out + in > VIRTNET_SEND_COMMAND_SG_MAX));

Signed-off-by: Huawei Xie <3b3be4428106761300a2ee559c9f71ecdb091553@intel.com>
Acked-by: Tetsuya Mukawa <b347a9f5840345582b30d055e1e99ac6ac7bce3c@igel.co.jp>

msune/dpdk,mixja/dpdk,mixja/dpdk,venkynv/dpdk-mirror,venkynv/dpdk-mirror,venkynv/dpdk-mirror,msune/dpdk,john-mcnamara-intel/dpdk,msune/dpdk,tsphillips/dpdk-fork,tsphillips/dpdk-fork,tsphillips/dpdk-fork,john-mcnamara-intel/dpdk,tsphillips/dpdk-fork,venkynv/dpdk-mirror,john-mcnamara-intel/dpdk,mixja/dpdk,msune/dpdk,john-mcnamara-intel/dpdk,mixja/dpdk