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>