dt-bindings: phy: Add binding for TI TCAN104x CAN transceivers

Add binding documentation for TI TCAN104x CAN transceivers.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>