ipq40xx: add open-drain support to pinctrl-msm

ipq40xx: add open-drain support to pinctrl-msm

Submitted upstream. Shouldn't affect existing devices, but enables new
device support.

https://lore.kernel.org/linux-gpio/20200703080646.23233-1-computersforpeace@gmail.com/

Currently queued for-next:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git/commit/?h=for-next&id=13355ca35cd16f5024655ac06e228b3c199e52a9

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
[refresh patch]
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>