arm64: dts: qcom: sdm630-nile: Add RGB status LED on the PM660L LPG

The entire Sony Nile and Ganges lineup utilize the first three channels
(the triled channels) of the LPG block for an RGB (battery) status and
notification indicator.

Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
[bjorn: Dropped #address/#size-cells]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220511190718.764445-4-marijn.suijten@somainline.org