UPSTREAM: pinctrl: rockchip: Add iomux-route switching support for rk3228

UPSTREAM: pinctrl: rockchip: Add iomux-route switching support for rk3228

There are 9 IP blocks pin routes need to be switched, that are
pwm-0, pwm-1, pwm-2, pwm-3, sdio, spi, emmc, uart2, uart1.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
(cherry picked from git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git for-next
 commit d4970ee076f9aed396c322b41f56443a617116df)

Signed-off-by: David Wu <david.wu@rock-chips.com>
Change-Id: I9e4fbfb22f37add2ba5941b2b2ae9e55ed2d28b8