dt-bindings: leds: Add pm8350c pmic support

Add pm8350c pmic pwm support.

Signed-off-by: Satya Priya <quic_c_skakit@quicinc.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>