HID: macally: Constify macally_id_table

macally_id_table is not modified and can be made const to allow the
compiler to put it in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

HID: macally: Add support for Macally ikey keyboard

This enables the power and equals keys on the Macally ikey keyboard.

Based on the Cougar gaming keyboard HID driver, which uses the same
vendor ID.

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>