sh-pfc: Replace SoC info data and mark ranges with a number of pins

The data and mark ranges are only used to check whether a GPIO
corresponds to a real pin or a function. As pins come first in the list
of GPIOs and in the platform-specific GPIO enumerations, we can replace
the data and mark ranges by a number of pins.

Add an nr_pins field to struct sh_pfc_soc_info to store the number of
pins implemented by the SoC, remove the data and mark range fields and
introduce sh_pfc_gpio_is_pin() and sh_pfc_gpio_is_function() functions
to replace range-based checks.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>