The irq_to_gpio() is old, most platforms use GENERIC_GPIO framework
and don't support this API anymore.
The i.MX6q sabrelite platform equips an egalax touchscreen controller,
and this platform already transfered to GENERIC_GPIO framework, to
support this driver, we use a more generic way to get gpio.
Add a return value checking for waking up the controller in the probe
function, this guarantee only a workable device can pass init.
[dmitry.torokhov@gmail.com: Make driver depend on CONFIG_OF as it is
now required.]