Input: imx_keypad - remove obsolete comment

Since commit 81e8f2bc (Input: imx_keypad - add pm suspend and resume
support) the imx_keypad driver supports power management, so let's remove
the obsolete comment.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/imx_keypad.c

@@ -5,8 +5,6 @@
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
- * <<Power management needs to be implemented>>.
  */
 
 #include <linux/clk.h>