pinctrl: rockchip: rename RK1108 to RV1108

Rockchip finally named the SOC as RV1108, so change it.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
[adapted rk1108 dtsi to keep bisectability]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>