Move blkiodev package to types.

Signed-off-by: David Calavera <david.calavera@gmail.com>

types/blkiodev/blkio.go

@@ -0,0 +1,23 @@
+package blkiodev
+
+import "fmt"
+
+// WeightDevice is a structure that hold device:weight pair
+type WeightDevice struct {
+	Path   string
+	Weight uint16
+}
+
+func (w *WeightDevice) String() string {
+	return fmt.Sprintf("%s:%d", w.Path, w.Weight)
+}
+
+// ThrottleDevice is a structure that hold device:rate_per_second pair
+type ThrottleDevice struct {
+	Path string
+	Rate uint64
+}
+
+func (t *ThrottleDevice) String() string {
+	return fmt.Sprintf("%s:%d", t.Path, t.Rate)
+}