HID: Add driver for ION iCade

Add a driver for the ION iCade mini arcade cabinet [1]. The device generates a
key press and release for each joystick movement or button press or release.
For example, moving the stick to the left will generate the "A" key being
pressed and then released.

A list of all the combinations is available in the iCade developer guide [2].

This driver hides all this and makes the device work as a generic joystick.

[1]: http://www.ionaudio.com/products/details/icade
[2]: http://www.ionaudio.com/downloads/iCade_Dev_Resource_v1.3.pdf

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 269b509..9bc8d57 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -420,6 +420,9 @@
 #define USB_VENDOR_ID_ILITEK		0x222a
 #define USB_DEVICE_ID_ILITEK_MULTITOUCH	0x0001
 
+#define USB_VENDOR_ID_ION		0x15e4
+#define USB_DEVICE_ID_ICADE		0x0132
+
 #define USB_VENDOR_ID_HOLTEK		0x1241
 #define USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP	0x5015