net: dsa: mt7530: empty default case on mt7530_setup_port5()

There're two code paths for setting up port 5:

mt7530_setup()
-> mt7530_setup_port5()

mt753x_phylink_mac_config()
-> mt753x_mac_config()
   -> mt7530_mac_config()
      -> mt7530_setup_port5()

On the first code path, priv->p5_intf_sel is either set to
P5_INTF_SEL_PHY_P0 or P5_INTF_SEL_PHY_P4 when mt7530_setup_port5() is run.

On the second code path, priv->p5_intf_sel is set to P5_INTF_SEL_GMAC5 when
mt7530_setup_port5() is run.

Empty the default case which will never run but is needed nonetheless to
handle all the remaining enumeration values.
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Link: https://lore.kernel.org/r/20240206-for-netnext-mt7530-improvements-2-v5-1-d7d92a185cb1@arinc9.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mt7530.c

@@ -943,9 +943,7 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
 		val &= ~MHWTRAP_P5_DIS;
 		break;
 	default:
-		dev_err(ds->dev, "Unsupported p5_intf_sel %d\n",
-			priv->p5_intf_sel);
-		goto unlock_exit;
+		break;
 	}
 
 	/* Setup RGMII settings */
@@ -975,7 +973,6 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
 	dev_dbg(ds->dev, "Setup P5, HWTRAP=0x%x, intf_sel=%s, phy-mode=%s\n",
 		val, p5_intf_modes(priv->p5_intf_sel), phy_modes(interface));
 
-unlock_exit:
 	mutex_unlock(&priv->reg_mutex);
 }