dt-bindings: arm: fsl: Add Traverse Ten64 (LS1088A) board

Document the compatible for the Ten64 board which will
be included as freescale/fsl-ls1088a-ten64.dtb in arm64.

Signed-off-by: Mathew McBride <matt@traverse.com.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>