sh-pfc: r8a7779: Add USB0 and USB1 PENC pinmux support

The USB0 and USB1 PENC functions were missing. Add them.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>