sh-pfc: Merge sh_pfc_reconfig_pin() into sh_pfc_gpio_set_direction()

The sh_pfc_reconfig_pin() is only called from a single location. Merge
it into its call site to make the code easier to follow.

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