arm64: dts: qcom: msm8916-longcheer-l8150: Add flash LED

L8150 uses SGM3785 Flash LED driver. It is similar to SGM3140 but
can also be controlled with PWM. Since SoC doesn't have PWM, add
led to the device tree using sgm3140 driver.

Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Nikita Travkin <nikitos.tr@gmail.com>
Link: https://lore.kernel.org/r/20201113175917.189123-4-nikitos.tr@gmail.com


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>