ARM: imx6ul: Fix Micrel PHY mask

The value used for Micrel PHY mask is not correct. Use the
MICREL_PHY_ID_MASK definition instead.

Thanks to Jiri Luznicky for proposing the fix at
https://community.freescale.com/thread/387739

Cc: <stable@vger.kernel.org>
Fixes: 709bc0657fe6f9f55 ("ARM: imx6ul: add fec MAC refrence clock and phy fixup init")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/mach-imx/mach-imx6ul.c

@@ -46,7 +46,7 @@ static int ksz8081_phy_fixup(struct phy_device *dev)
 static void __init imx6ul_enet_phy_init(void)
 {
 	if (IS_BUILTIN(CONFIG_PHYLIB))
-		phy_register_fixup_for_uid(PHY_ID_KSZ8081, 0xffffffff,
+		phy_register_fixup_for_uid(PHY_ID_KSZ8081, MICREL_PHY_ID_MASK,
 					   ksz8081_phy_fixup);
 }