HID: support for Kensington slimblade device

0x47d/0x2041 device sends two extra buttons in 0xff00 usage
page and therefore requires special handling.

Reported-by: Jason Noble <nobleja@polezero.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-dummy.c b/drivers/hid/hid-dummy.c
index 536aa15..28815fd 100644
--- a/drivers/hid/hid-dummy.c
+++ b/drivers/hid/hid-dummy.c
@@ -37,6 +37,9 @@
 #ifdef CONFIG_HID_GYRATION_MODULE
 	HID_COMPAT_CALL_DRIVER(gyration);
 #endif
+#ifdef CONFIG_HID_KENSINGTON_MODULE
+	HID_COMPAT_CALL_DRIVER(kensington);
+#endif
 #ifdef CONFIG_HID_LOGITECH_MODULE
 	HID_COMPAT_CALL_DRIVER(logitech);
 #endif