Input: ep93xx_keypad - add missing include of linux/module.h

ep93xx_keypad.c uses interfaces from linux/module.h,
so it should include that file.  This patch fixes build errors.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/keyboard/ep93xx_keypad.c b/drivers/input/keyboard/ep93xx_keypad.c
index c8242dd..aa17e02 100644
--- a/drivers/input/keyboard/ep93xx_keypad.c
+++ b/drivers/input/keyboard/ep93xx_keypad.c
@@ -20,6 +20,7 @@
  * flag.
  */
 
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/clk.h>