arm64: dts: qcom: sdm632-fairphone-fp3: Add notification LED

The phone features a notification LED connected to the pmi632. Configure
the RGB led found on it.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230414-pmi632-v3-2-079d2cada699@z3ntu.xyz