sh-pfc: sh73a0: Remove pull-up function GPIOS

All sh73a0 platforms now use the pinconf API to control pull-ups, the
corresponding function GPIOS are unused. Remove them.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>