pinctrl: qcom: Add msm8998 pinctrl driver

Add initial pinctrl driver to support pin configuration with
pinctrl framework for msm8998.

Signed-off-by: Imran Khan <kimran@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
[bjorn: Consolidated function groups]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>