Input: ft6236 - change module license string to match copyright notice

The copyright/license notice says that the code is licensed under GPL v2
only (not GPL v2+), so let's use proper string in MODULE_LICENSE().
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/ft6236.c

@@ -323,4 +323,4 @@ module_i2c_driver(ft6236_driver);
 MODULE_AUTHOR("Sean Cross <xobs@kosagi.com>");
 MODULE_AUTHOR("Noralf Trønnes <noralf@tronnes.org>");
 MODULE_DESCRIPTION("FocalTech FT6236 TouchScreen driver");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");