net/fsl: xgmac_mdio: Fix spelling mistake "frequecy" -> "frequency"

There is a spelling mistake in a dev_err message. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/xgmac_mdio.c

@@ -276,7 +276,7 @@ static int xgmac_mdio_set_mdc_freq(struct mii_bus *bus)
 
 	div = ((clk_get_rate(priv->enet_clk) / priv->mdc_freq) - 1) / 2;
 	if (div < 5 || div > 0x1ff) {
-		dev_err(dev, "Requested MDC frequecy is out of range, ignoring");
+		dev_err(dev, "Requested MDC frequency is out of range, ignoring");
 		return -EINVAL;
 	}