powercap/drivers/dtpm: Reduce trace verbosity

The traces when registering a powerzone is at the pr_info level and
should be changed to pr_debug as requested by Greg-KH.

Cc: Greg KH <gregkh@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/YGAnRx8SiZHFPpY6@kroah.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20211123101601.2433340-2-daniel.lezcano@linaro.org