Power: Changes the permission to read only for sysfs file

/sys/kernel/wakeup_reasons/last_resume_reason

Change-Id: I8ac568a7cb58c31decd379195de517ff3c6f9c65
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Git-commit: 70dc3ed48fb6c02d2c651505d41f8988570f2f81
Git-repo: https://android.googlesource.com/kernel/common.git


Signed-off-by: Ian Maund <imaund@codeaurora.org>