pmdomain: raspberrypi-power: Add logging to rpi_firmware_set_power

pmdomain: raspberrypi-power: Add logging to rpi_firmware_set_power

The Raspberry Pi power driver heavily relies on the logging of the
underlying firmware driver. This results in disadvantages like unspecific
error messages or limited debugging options. So implement the logging for
the most important function rpi_firmware_set_power.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240728114200.75559-5-wahrenst@gmx.net
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>