arm64: dts: qcom: sdm845-xiaomi-beryllium: add notification LED

The Poco F1 has a single color white notification LED. Enable the
Qualcomm Light Pulse Generator (LPG) driver based notification LED.

Signed-off-by: Joel Selvaraj <joelselvaraj.oss@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230313154226.136726-1-joelselvaraj.oss@gmail.com