arm64: dts: qcom: pm8150b: add Light Pulse Generator device node

Add device node defining LPG/PWM block on PM8150B PMIC chip.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220505145102.1432670-2-dmitry.baryshkov@linaro.org