sh-pfc: r8a7790: Rename I2C SDA/SCL pins

The I2C pins have been renamed in the datasheet, rename them here as
well.
Signed-off-by: NShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>