sh-pfc: Merge PFC core and pinctrl

The PFC core is only used by the pinctrl and gpio modules. As the gpio
module depends on the pinctrl module, the pinctrl module will always be
present if the core gets used. There is thus no point in keeping core
and pinctrl in two seperate modules. Merge them.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>