serial: clps711x: Changing the compatibility string to match with the smallest supported chip

This patch changes the compatibility string to match with the smallest
supported chip (EP7209). Since the DT-support for this CPU is not yet
announced, this change is safe.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/serial/cirrus,clps711x-uart.txt

 * Cirrus Logic CLPS711X Universal Asynchronous Receiver/Transmitter (UART)
 
 Required properties:
-- compatible: Should be "cirrus,clps711x-uart".
+- compatible: Should be "cirrus,ep7209-uart".
 - reg: Address and length of the register set for the device.
 - interrupts: Should contain UART TX and RX interrupt.
 - clocks: Should contain UART core clock number.
@@ -20,7 +20,7 @@ Example:
 	};
 
 	uart1: uart@80000480 {
-		compatible = "cirrus,clps711x-uart";
+		compatible = "cirrus,ep7312-uart","cirrus,ep7209-uart";
 		reg = <0x80000480 0x80>;
 		interrupts = <12 13>;
 		clocks = <&clks 11>;

drivers/tty/serial/clps711x.c

@@ -539,7 +539,7 @@ static int uart_clps711x_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
-	{ .compatible = "cirrus,clps711x-uart", },
+	{ .compatible = "cirrus,ep7209-uart", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, clps711x_uart_dt_ids);