examples/vhost: remove DMA type option help info
examples/vhost: remove DMA type option help info

The dma-type parameter was not supported when dmadev was
integrated in vhost, but the help info still exists. This
patch deletes it.

Fixes: 53d3f4778c1d ("vhost: integrate dmadev in asynchronous data-path")

Signed-off-by: Chengwen Feng <af69652d70a703aa3bb4268f61750255b6f8fb91@huawei.com>
Reviewed-by: Chenbo Xia <5d298a4585cd22ca5d29de25967a5599c4c324c8@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk