Since gpio driver could create gpio range in DTS, it could invoke
pinctrl_request_gpio(). In the pinctrl-single driver, it needs to
configure pins with gpio function mode.
A new gpio function range should be created in DTS file in below.
2. gpio driver could get pin offset from gpio-ranges property.
pinctrl-single driver could get gpio function mode from gpio_func
that is stored in @gpiofuncs list in struct pcs_device.
This new pinctrl-single,gpio-range is used as complement for
gpio-ranges property in gpio driver.