net: dsa: mv88e6xxx: Remove stale comment

GPIOF_DIR_* definitions are legacy and subject to remove.
Taking this into account, remove stale comment.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20240827171005.2301845-1-andriy.shevchenko@linux.intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mv88e6xxx/global2_scratch.c

@@ -146,7 +146,7 @@ static int mv88e6352_g2_scratch_gpio_set_data(struct mv88e6xxx_chip *chip,
  * @chip: chip private data
  * @pin: gpio index
  *
- * Return: 0 for output, 1 for input (same as GPIOF_DIR_XXX).
+ * Return: 0 for output, 1 for input.
  */
 static int mv88e6352_g2_scratch_gpio_get_dir(struct mv88e6xxx_chip *chip,
 					     unsigned int pin)