drivers: tty: goldfish: Add device tree bindings

Enable support for registering this device using the device tree.
Device tree node example for registering Goldfish TTY device :

goldfish_tty@1f004000 {
interrupts = <0xc>;
reg = <0x1f004000 0x1000>;
compatible = "google,goldfish-tty";
};

Signed-off-by: Miodrag Dinic <[e-mail]>
Signed-off-by: Jin Qian <[e-mail]>
Signed-off-by: Alan <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/goldfish/tty.txt

···
+Android Goldfish TTY
+
+Android goldfish tty device generated by android emulator.
+
+Required properties:
+
+- compatible : should contain "google,goldfish-tty" to match emulator
+- reg        : <registers mapping>
+- interrupts : <interrupt mapping>
+
+Example:
+
+	goldfish_tty@1f004000 {
+		compatible = "google,goldfish-tty";
+		reg = <0x1f004000 0x1000>;
+		interrupts = <0xc>;
+	};

drivers/tty/goldfish.c

···
 	return 0;
 }
 
+static const struct of_device_id goldfish_tty_of_match[] = {
+	{ .compatible = "google,goldfish-tty", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
+
 static struct platform_driver goldfish_tty_platform_driver = {
 	.probe = goldfish_tty_probe,
 	.remove = goldfish_tty_remove,
 	.driver = {
-		.name = "goldfish_tty"
+		.name = "goldfish_tty",
+		.of_match_table = goldfish_tty_of_match,
 	}
 };