Support adding devices by dir

This enables cases where devices exist in a subdirectory of /dev,
particularly where those device names are not portable across machines,
which makes it problematic to specify from a runtime such as cri.

Added this to `ctr` as well so I could test that the code at least
works.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

cmd/ctr/commands/run/run_unix.go

@@ -264,7 +264,7 @@ func NewContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 			opts = append(opts, oci.WithMemoryLimit(limit))
 		}
 		for _, dev := range context.StringSlice("device") {
-			opts = append(opts, oci.WithLinuxDevice(dev, "rwm"))
+			opts = append(opts, oci.WithDevices(dev, "", "rwm"))
 		}
 	}