net: phy: mscc: remove unnecessary phydev locking

Holding the struct phy_device (phydev) lock is unnecessary when
accessing phydev->interface in the PHY driver .config_init method,
which is the only place that vsc85xx_rgmii_set_skews() is called from.

The phy_modify_paged() function implements required MDIO bus level
locking, which can not be achieved by a phydev lock.
Signed-off-by: David Epping <david.epping@missinglinkelectronics.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/mscc/mscc_main.c

@@ -528,8 +528,6 @@ static int vsc85xx_rgmii_set_skews(struct phy_device *phydev, u32 rgmii_cntl,
 	u16 reg_val = 0;
 	int rc;
 
-	mutex_lock(&phydev->lock);
-
 	if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
 	    phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
 		reg_val |= RGMII_CLK_DELAY_2_0_NS << rgmii_rx_delay_pos;
@@ -542,8 +540,6 @@ static int vsc85xx_rgmii_set_skews(struct phy_device *phydev, u32 rgmii_cntl,
 			      rgmii_rx_delay_mask | rgmii_tx_delay_mask,
 			      reg_val);
 
-	mutex_unlock(&phydev->lock);
-
 	return rc;
 }