PM / devfreq: bw_hwmon: Remove debug logs from high frequency code path

Using debug logs for the short samples would result in excessive logging
and also have an impact on CPU power and performance. The tracepoint that's
already there is a much better alternative. So, delete the debug logs.

Change-Id: Idd1d634f510381d14637f3b84588a118572f3f16
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>