net: tlan: Fix typo abitrary

Fix comment typo.
s/abitrary/arbitrary/

Signed-off-by: Naoki Hayama <naoki.hayama@lineo.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/ti/tlan.c

@@ -2511,7 +2511,7 @@ static void tlan_phy_power_down(struct net_device *dev)
 	}
 
 	/* Wait for 50 ms and powerup
-	 * This is abitrary.  It is intended to make sure the
+	 * This is arbitrary.  It is intended to make sure the
 	 * transceiver settles.
 	 */
 	tlan_set_timer(dev, msecs_to_jiffies(50), TLAN_TIMER_PHY_PUP);