net: phy: smsc: add comments for the LAN8742 phy ID mask.

add comments for the LAN8742 phy ID mask in the previous patch.
add one missing tab in the LAN8742 phy ID line.
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/smsc.c

@@ -484,7 +484,11 @@ static struct phy_driver smsc_phy_driver[] = {
 	.suspend	= genphy_suspend,
 	.resume		= genphy_resume,
 }, {
-	.phy_id	= 0x0007c130,	/* 0x0007c130 and 0x0007c131 */
+	.phy_id		= 0x0007c130,	/* 0x0007c130 and 0x0007c131 */
+	/* This mask (0xfffffff2) is to differentiate from
+	 * LAN88xx (phy_id 0x0007c132)
+	 * and allows future phy_id revisions.
+	 */
 	.phy_id_mask	= 0xfffffff2,
 	.name		= "Microchip LAN8742",