1) Move GPIO-related functionality to qdev. Now one can use directly
qdev_get_gpio_in()/qdev_connect_gpio_out() on max7310 devices.

2) Make reset to be called through qdev.reset callback.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>