Many nodes in the MSM8916 device trees use '_' in node names
(especially pinctrl), even though (seemingly) '-' is preferred now.
Make this more consistent by replacing '_' with '-' where possible.

Similar naming is used for pinctrl in newer device trees (e.g. sdm845.dtsi).
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20200514112754.148919-1-stephan@gerhold.netSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>