net, davinci_emac: make less verbose - turn printf() into debug()

The PHY driver was too verbose and corrupted the boot message display
like this:

...
Net:   Ethernet PHY: KSZ8873 @ 0x02
DaVinci-EMAC
...

Turn printf() into debug() so we get the expected output again:

...
Net:   DaVinci-EMAC
...

Signed-off-by: Heiko Schocher <hs@denx.de>
cc: Paulraj Sandeep <s-paulraj@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

drivers/net/davinci_emac.c

@@ -747,7 +747,7 @@ int davinci_emac_initialize(void)
 			phy.auto_negotiate = gen_auto_negotiate;
 	}
 
-	printf("Ethernet PHY: %s\n", phy.name);
+	debug("Ethernet PHY: %s\n", phy.name);
 
 	miiphy_register(phy.name, davinci_mii_phy_read, davinci_mii_phy_write);
 	return(1);