pinctrl: renesas: r8a779g0: Add Audio SSI pins, groups, and functions

Add pins, groups, and functions for the Serial Sound Interface (SSI) on
the Renesas R-Car V4H (R8A779G0) SoC.

Signed-off-by: Linh Phung <linh.phung.jy@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/87bkmcang2.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>