soc: qcom: add ADSP PDCharger ULOG driver

The Qualcomm PMIC PDCharger ULOG driver provides access to logs of
the ADSP firmware PDCharger module in charge of Battery and Power
Delivery on modern systems.

Implement trace events as a simple rpmsg driver with an 1s interval
to retrieve the messages.

The interface allows filtering the messages by subsystem and priority
level, this could be implemented later on.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230908-topic-sm8550-upstream-pdcharge-ulog-v1-1-d1b16b02ced2@linaro.org


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