pinctrl: rockchip: rockchip_pinctrl in rockchip_get_bank_data

Convert rockchip_get_bank_data to use the struct rockchip_pinctrl because
later on we need to check a value from it when registering the gpio banks.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>