pinctrl: sh-pfc: r8a77470: Add USB pin groups

Add USB[01] pin groups and functions to the R8A77470 SoC.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>