Jetson TK1 contains an RT5639 not an RT5640. While the two are extremely
similar and mostly compatible, we should still use the correct device
name in the device tree. I had meant to fix this before applying the
initial DT, but this issue slipped my mind.
Signed-off-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thierry Reding <treding@nvidia.com>