net: axienet: Unexport and remove unused mdio functions

Both axienet_mdio_{enable/disable} functions are no longer used in
xilinx_axienet_main.c due to 253761a0e61b7. And axienet_mdio_disable is
not even used in the mdio.c. So unexport and remove them.

Signed-off-by: Andy Chiu <[e-mail]>
Reviewed-by: Greentime Hu <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/xilinx/xilinx_axienet.h

···
 #endif /* CONFIG_64BIT */
 
 /* Function prototypes visible in xilinx_axienet_mdio.c for other files */
-int axienet_mdio_enable(struct axienet_local *lp);
-void axienet_mdio_disable(struct axienet_local *lp);
 int axienet_mdio_setup(struct axienet_local *lp);
 void axienet_mdio_teardown(struct axienet_local *lp);
 

drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c

···
  * Sets up the MDIO interface by initializing the MDIO clock and enabling the
  * MDIO interface in hardware.
  **/
-int axienet_mdio_enable(struct axienet_local *lp)
+static int axienet_mdio_enable(struct axienet_local *lp)
 {
 	u32 host_clock;
 
···
 	axienet_iow(lp, XAE_MDIO_MC_OFFSET, lp->mii_clk_div | XAE_MDIO_MC_MDIOEN_MASK);
 
 	return axienet_mdio_wait_until_ready(lp);
-}
-
-/**
- * axienet_mdio_disable - MDIO hardware disable function
- * @lp:		Pointer to axienet local data structure.
- *
- * Disable the MDIO interface in hardware.
- **/
-void axienet_mdio_disable(struct axienet_local *lp)
-{
-	axienet_iow(lp, XAE_MDIO_MC_OFFSET, 0);
 }
 
 /**