pinctrl: pfc: r8a7790: add i2c0 muxing

Add the muxing for the last missing i2c rcar core. Fix the sorting for
SH_PFC_PIN_NAMED while we are here.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>