doc: DT: Add ti,da830-uart to serial/8250 bindings

This adds the ti,da830-uart compatible string to serial 8250 UART bindings.
Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/8250.txt

@@ -19,6 +19,7 @@ Required properties:
 	- "altr,16550-FIFO128"
 	- "fsl,16550-FIFO64"
 	- "fsl,ns16550"
+	- "ti,da830-uart"
 	- "serial" if the port type is unknown.
 - reg : offset and length of the register set for the device.
 - interrupts : should contain uart interrupt.