net: mvmdio: allow up to four clocks to be specified for orion-mdio

Allow up to four clocks to be specified and enabled for the orion-mdio
interface, which are required by the Armada 8k and defined in
armada-cp110.dtsi.

Fixes a hang in probing the mvmdio driver that was encountered on the
Clearfog GT 8K with all drivers built as modules, but also affects other
boards such as the MacchiatoBIN.

Cc: stable@vger.kernel.org
Fixes: 96cb434 ("net: mvmdio: allow up to three clocks to be specified for orion-mdio")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvmdio.c

@@ -64,7 +64,7 @@
 
 struct orion_mdio_dev {
 	void __iomem *regs;
-	struct clk *clk[3];
+	struct clk *clk[4];
 	/*
 	 * If we have access to the error interrupt pin (which is
 	 * somewhat misnamed as it not only reflects internal errors