pinctrl: sh-pfc: r8a7795-es1: Add I2C{0,3,5} pins, groups and functions

This patch adds I2C{0,3,5} pins, groups and functions to
the R8A7795 ES1.x SoC.

These pins are physically muxed with other pins. Therefore, setup of
MOD_SEL is needed for exclusive control with other pins.

Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>