HID: asus: Add T100CHI bluetooth keyboard dock special keys mapping

The Asus Transformer T100CHI comes with a Bluetooth keyboard dock which
uses the same 0xff31 Asus vendor HUT page as other Asus keyboards.

This commit adds its device-id to hid-asus and fixes an issue in the
descriptor of the 0xff31 Usage, which together fixes the special keys
on this keyboard not working.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 3d911bf..1093595 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -176,6 +176,7 @@
 #define USB_DEVICE_ID_ASUSTEK_LCM	0x1726
 #define USB_DEVICE_ID_ASUSTEK_LCM2	0x175b
 #define USB_DEVICE_ID_ASUSTEK_T100_KEYBOARD	0x17e0
+#define USB_DEVICE_ID_ASUSTEK_T100CHI_KEYBOARD	0x8502
 #define USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD	0x8585
 #define USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD	0x0101
 #define USB_DEVICE_ID_ASUSTEK_ROG_KEYBOARD1 0x1854