pinctrl: sh-pfc: r8a7796: Add VIN4, VIN5 pins, groups and functions

This patch adds VIN4 and VIN5 pins, groups and functions for the
R8A7796 SoC.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>