pinctrl: sh-pfc: Store register/field widths in u8 instead of unsigned long

Register and field widths are in the range 1..32. Storing them in the
pinctrl data in (arrays of) unsigned long wastes space.

This decreases the size of a (32-bit) shmobile_defconfig kernel
supporting 7 SoCs by 26460 bytes.

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