pinctrl: qcom: ipq4019: add open drain support

[ Brian: adapted from from the Chromium OS kernel used on IPQ4019-based
  WiFi APs. ]

Signed-off-by: Jaiganesh Narayanan <njaigane@codeaurora.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Link: https://lore.kernel.org/r/20200703080646.23233-1-computersforpeace@gmail.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>