pinctrl: sh-pfc: r8a7795: add SCIFx support

This patch adds SCIF0/1/2/3/4/5

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[Morimoto-san: Updated]
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>