common: Move mii_init() function out of common.h

This function belongs in mii.h so move it over.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/net/fsl_mcdmafec.c b/drivers/net/fsl_mcdmafec.c
index e66fb16..b2936b7 100644
--- a/drivers/net/fsl_mcdmafec.c
+++ b/drivers/net/fsl_mcdmafec.c
@@ -14,6 +14,7 @@
 #include <config.h>
 #include <net.h>
 #include <miiphy.h>
+#include <linux/mii.h>
 
 #undef	ET_DEBUG
 #undef	MII_DEBUG