dt-bindings: pinctrl: qcom: Add SM8350 pinctrl bindings

Add device tree binding Documentation details for Qualcomm SM8350
pinctrl driver.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210205140132.274242-2-vkoul@kernel.org


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