HID: apple: Add support for the 2015 Macbook Pro

This patch adds keyboard support for MacbookPro12,1 as WELLSPRING9
(0x0272, 0x0273, 0x0274). The touchpad is handled in a separate
bcm5974 patch, as usual.

Tested-by: John Horan <knasher@gmail.com>
Tested-by: Jochen Radmacher <jradmacher@gmx.de>
Tested-by: Yang Hongyang <burnef@gmail.com>
Tested-by: Yen-Chin, Lee <coldnew.tw@gmail.com>
Tested-by: George Hilios <ghilios@gmail.com>
Tested-by: Janez Urevc <janez@janezurevc.name>
Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>