net: dsa: qca8k: move qca8k_port_to_phy() to header

Move qca8k_port_to_phy() to qca8k header as it's useful for future
reference in Switch LEDs module since the same logic is applied to get
the right index of the switch port.
Make it inline as it's simple function that just decrease the port.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/qca/qca8k-8xxx.c

@@ -772,21 +772,6 @@ qca8k_phy_eth_command(struct qca8k_priv *priv, bool read, int phy,
 	return ret;
 }
 
-static u32
-qca8k_port_to_phy(int port)
-{
-	/* From Andrew Lunn:
-	 * Port 0 has no internal phy.
-	 * Port 1 has an internal PHY at MDIO address 0.
-	 * Port 2 has an internal PHY at MDIO address 1.
-	 * ...
-	 * Port 5 has an internal PHY at MDIO address 4.
-	 * Port 6 has no internal PHY.
-	 */
-
-	return port - 1;
-}
-
 static int
 qca8k_mdio_busy_wait(struct mii_bus *bus, u32 reg, u32 mask)
 {

drivers/net/dsa/qca/qca8k.h

@@ -421,6 +421,20 @@ struct qca8k_fdb {
 	u8 mac[6];
 };
 
+static inline u32 qca8k_port_to_phy(int port)
+{
+	/* From Andrew Lunn:
+	 * Port 0 has no internal phy.
+	 * Port 1 has an internal PHY at MDIO address 0.
+	 * Port 2 has an internal PHY at MDIO address 1.
+	 * ...
+	 * Port 5 has an internal PHY at MDIO address 4.
+	 * Port 6 has no internal PHY.
+	 */
+
+	return port - 1;
+}
+
 /* Common setup function */
 extern const struct qca8k_mib_desc ar8327_mib[];
 extern const struct regmap_access_table qca8k_readable_table;