net: phy: mdio: add missing __iomem annotation

Added missing __iomem annotation in order to fix the following
sparse warnings:

drivers/net/phy/mdio-mux-mmioreg.c:51:27: warning: incorrect type in initializer (different address spaces)
drivers/net/phy/mdio-mux-mmioreg.c:51:27:    expected void *p
drivers/net/phy/mdio-mux-mmioreg.c:51:27:    got void [noderef] <asn:2>*
drivers/net/phy/mdio-mux-mmioreg.c:57:21: warning: incorrect type in argument 1 (different address spaces)
drivers/net/phy/mdio-mux-mmioreg.c:57:21:    expected void const volatile [noderef] <asn:2>*addr
drivers/net/phy/mdio-mux-mmioreg.c:57:21:    got void *p
drivers/net/phy/mdio-mux-mmioreg.c:60:25: warning: incorrect type in argument 2 (different address spaces)
drivers/net/phy/mdio-mux-mmioreg.c:60:25:    expected void volatile [noderef] <asn:2>*addr
drivers/net/phy/mdio-mux-mmioreg.c:60:25:    got void *p
drivers/net/phy/mdio-mux-mmioreg.c:64:25: warning: incorrect type in argument 1 (different address spaces)
drivers/net/phy/mdio-mux-mmioreg.c:64:25:    expected void volatile [noderef] <asn:2>*addr
drivers/net/phy/mdio-mux-mmioreg.c:64:25:    got void *p
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio-mux-mmioreg.c

@@ -48,7 +48,7 @@ static int mdio_mux_mmioreg_switch_fn(int current_child, int desired_child,
 	struct mdio_mux_mmioreg_state *s = data;
 
 	if (current_child ^ desired_child) {
-		void *p = ioremap(s->phys, 1);
+		void __iomem *p = ioremap(s->phys, 1);
 		uint8_t x, y;
 
 		if (!p)