classmate-laptop: Added some keys present in other devices

Some new devices have extra keys, which we add to our list. Currently,
they all generate events that allow us to use a simple table/array,
without need for the sparse keymap.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>

drivers/platform/x86/classmate-laptop.c

@@ -507,6 +507,10 @@ static int cmpc_keys_codes[] = {
 	KEY_BRIGHTNESSDOWN,
 	KEY_BRIGHTNESSUP,
 	KEY_VENDOR,
+	KEY_UNKNOWN,
+	KEY_CAMERA,
+	KEY_BACK,
+	KEY_FORWARD,
 	KEY_MAX
 };