Picking up Oliver's patches.

I've added Stephane's Acked-by to all patches.

Changes since v9:
- 3/7 + 4/7
  I moved the simplified "if" in can_get_bittiming() from 4/7 into 3/7,
  so the more complicated if is not introduced in the first place.
- 5/7
  In can_changelink(), when setting the data bittining, I removed the call to
  priv->do_set_data_bittiming().
  Further I moved the new "if (data[IFLA_CAN_DATA_BITTIMING])" at the bottom,
  so that all "if"s are sorted by "IFLA_".
- 6/7
  can_change_mtu(): fix indention after "default" in "switch"

Marc