powerdk: update wakelock tracepoint

powerdk: update wakelock tracepoint

BZ 31198

Fix from Lim Min Yeol that:
1. Moves trace function inside spinlock because wakelock pointer could
get invalidated during a tracing event
2. Polishes output

Change-Id: I3f4f7a0560f5a4494e3d85a7e1bd76ed77fba44e
Signed-off-by: Lim Min Yeol <min.yeol.lim@intel.com>
Signed-off-by: German Monroy <german.monroy@intel.com>
Reviewed-on: http://android.intel.com:8080/42990
Reviewed-by: Zhang, Dongxing <dongxing.zhang@intel.com>
Reviewed-by: Kanigeri, Hari K <hari.k.kanigeri@intel.com>
Tested-by: Ng, Cheon-woei <cheon-woei.ng@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>