net: phy: adin: fix a warning about msleep

found a warning by the following command:
./scripts/checkpatch.pl -f drivers/net/phy/adin.c

WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.rst
 #628: FILE: drivers/net/phy/adin.c:628:
+	msleep(10);
Signed-off-by: NDejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/phy/adin.c

@@ -625,7 +625,7 @@ static int adin_soft_reset(struct phy_device *phydev)
 	if (rc < 0)
 		return rc;
 
-	msleep(10);
+	msleep(20);
 
 	/* If we get a read error something may be wrong */
 	rc = phy_read_mmd(phydev, MDIO_MMD_VEND1,