acp: Ensure dst mtime always greater or equal to src mtime

acp: Ensure dst mtime always greater or equal to src mtime

When copying files from file systems that support high resolution
mtime, we should not truncating the nsec part. Instead we should
increase the dst mtime by one sec to prevent dst mtime to become less
than src mtime.

Change-Id: I5cab1edd4b9783ec0e3ceb04ed833d8bbba00b19