Here a file to patch the kernel. It's modifying the hid_apple.c file to map F13, F14, F15 to PrintSc, ScrollLock and Pause. This modification apply only to Apple Slim Aluminium Keyboard (0003:05AC:0220.0004). I'm sure the modification can be apply to many more apple keyboard, so modify the patch as your wish.
Here a file to patch the kernel. It's modifying the hid_apple.c file to map F13, F14, F15 to PrintSc, ScrollLock and Pause. This modification apply only to Apple Slim Aluminium Keyboard (0003:05AC: 0220.0004) . I'm sure the modification can be apply to many more apple keyboard, so modify the patch as your wish.