net/miiphy/serial: drop duplicate "NAMESIZE" define

A few subsystems are using the same define "NAMESIZE".  This has been
working so far because they define it to the same number.  However, I
want to change the size of eth_device's NAMESIZE, so rather than tweak
the define names, simply drop references to it.  Almost no one does,
and the handful that do can easily be changed to a sizeof().

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/net/eth.c b/net/eth.c
index f14767b..aed4dd6 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -203,7 +203,7 @@
 	struct eth_device *d;
 	static int index = 0;
 
-	assert(strlen(dev->name) < NAMESIZE);
+	assert(strlen(dev->name) < sizeof(dev->name));
 
 	if (!eth_devices) {
 		eth_current = eth_devices = dev;