Add ftruncate into file operation calls

- Add truncate into file_operations
- Move truncate to be common for mountpt_operations and file_operations
- Modify all drivers to initialize the operations struct accordingly

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>

drivers/input/tsc2007.c

@@ -209,6 +209,7 @@ static const struct file_operations tsc2007_fops =
   NULL,            /* write */
   NULL,            /* seek */
   tsc2007_ioctl,   /* ioctl */
+  NULL,            /* truncate */
   tsc2007_poll     /* poll */
 #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
   , NULL           /* unlink */