Input: gpio-keys - allow disabling individual buttons in DT

Add support to disable buttons from DT via status property if given button
is not supported on given platforms. This will help re-using existing dtsi
files across multiple platforms.

Signed-off-by: Laxman Dewangan <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/keyboard/gpio_keys.c

···
 	if (!node)
 		return ERR_PTR(-ENODEV);
 
-	nbuttons = of_get_child_count(node);
+	nbuttons = of_get_available_child_count(node);
 	if (nbuttons == 0)
 		return ERR_PTR(-ENODEV);
 
···
 	of_property_read_string(node, "label", &pdata->name);
 
 	i = 0;
-	for_each_child_of_node(node, pp) {
+	for_each_available_child_of_node(node, pp) {
 		enum of_gpio_flags flags;
 
 		button = &pdata->buttons[i++];