dt-bindings: rockchip,pinctrl: rename RK1108 to RV1108

Rockchip finally named the SOC as RV1108, so change it.
Also move the compatible list to one compatible per line.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>