Add the PWM devicetree bindings for the PWM/LPG device present in Qualcomm PM8941 chipset. Also make the necessary changes to the driver to comply with the devicetree binding requirements. Change-Id: I8124e2541028719e5b747bc85ff548ac109a9735 Signed-off-by: Jay Chokshi <jchokshi@codeaurora.org>