Move typeurl registrations to runtime package

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

runtime/typeurl.go

@@ -0,0 +1,17 @@
+package runtime
+
+import (
+	"strconv"
+
+	"github.com/containerd/containerd/typeurl"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func init() {
+	// register TypeUrls for commonly marshaled external types
+	major := strconv.Itoa(specs.VersionMajor)
+	typeurl.Register(&specs.Spec{}, "opencontainers/runtime-spec", major, "Spec")
+	typeurl.Register(&specs.Process{}, "opencontainers/runtime-spec", major, "Process")
+	typeurl.Register(&specs.LinuxResources{}, "opencontainers/runtime-spec", major, "LinuxResources")
+	typeurl.Register(&specs.WindowsResources{}, "opencontainers/runtime-spec", major, "WindowsResources")
+}