HID: apple: Swap the Fn and Left Control keys on Apple keyboards

This patch allows users to swap the Fn and left Control keys on all Apple
keyboards: internal (e.g. Macbooks) and external (both wired and wireless).
The patch adds a new hid-apple module param: swap_fn_leftctrl (off by default).

Signed-off-by: Zakhar Semenov <mail@free5lot.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>