Input: gpio-keys - allow setting input device name in DT

Allow specifying name if input device via device tree property. This helps
userspace code to get name and perform proper event to key mapping in some
cases (for example, on Android).

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/gpio-keys.txt

@@ -6,6 +6,7 @@ Required properties:
 Optional properties:
 	- autorepeat: Boolean, Enable auto repeat feature of Linux input
 	  subsystem.
+	- label: String, name of the input device.
 
 Each button (key) is represented as a sub-node of "gpio-keys":
 Subnode properties:

drivers/input/keyboard/gpio_keys.c

@@ -645,6 +645,8 @@ gpio_keys_get_devtree_pdata(struct device *dev)
 
 	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
 
+	of_property_read_string(node, "label", &pdata->name);
+
 	i = 0;
 	for_each_child_of_node(node, pp) {
 		enum of_gpio_flags flags;