ifuse_getattr: add st_mtime support introduced in os 3.1
ifuse_getattr: add st_mtime support introduced in os 3.1

Signed-off-by: Matt Colyer <1fa2ef4755a9226cb9a0a4840bd89b158ac71391@colyer.name>

libimobiledevice/ifuse,libimobiledevice/ifuse