pinctrl: sh-pfc: r8a77990: Add CAN pins, groups and functions

This patch adds CAN{0,1} pins, groups and functions to the R8A77990 SoC.

Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>