I am not sure about doing this via iFile. I remember it could have been done a couple of firmware versions ago, I just don't remember if it's available for 5.0.1.
However, if you jailbroke with redsn0w, you can re-run the redsn0w executable file to activate the multigestures. Open redsn0w and select to jailbreak - only you MUST make sure the UNcheck the "Install Cydia" box.
I've done this myself (because I forgot to tick that mulitgestures box). However, what I don't remember is whether this restores your device (so that you have to re-install a backup to get everything back the way it was). So, it may be drastic in that you have to do everything over again - or it may be simple in that it puts the multigestures option.
Maybe someone else remembers?
Regardless, that's the only way I know to put multigestures on the iPad. So, as always, ensure you have a good backup (both in iTunes and of your Cydia tweaks) before you start. Cause, you never know...
Marilyn