npe: get mac address from environment

The environment is the canonical storage location of the mac address, so
we're killing off the global data location and moving everything to
querying the env directly.

The resulting code can also be simplified even further.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Stefan Roese <sr@denx.de>
CC: Ben Warren <biggerbadderben@gmail.com>
diff --git a/cpu/ixp/npe/npe.c b/cpu/ixp/npe/npe.c
index 03e3bf7..2e68689 100644
--- a/cpu/ixp/npe/npe.c
+++ b/cpu/ixp/npe/npe.c
@@ -565,25 +565,19 @@
 	struct eth_device *dev;
 	int eth_num = 0;
 	struct npe *p_npe = NULL;
+	uchar enetaddr[6];
 
 	for (eth_num = 0; eth_num < CONFIG_SYS_NPE_NUMS; eth_num++) {
 
 		/* See if we can actually bring up the interface, otherwise, skip it */
-		switch (eth_num) {
-		default:		/* fall through */
-		case 0:
-			if (memcmp (bis->bi_enetaddr, "\0\0\0\0\0\0", 6) == 0) {
-				continue;
-			}
-			break;
 #ifdef CONFIG_HAS_ETH1
-		case 1:
-			if (memcmp (bis->bi_enet1addr, "\0\0\0\0\0\0", 6) == 0) {
+		if (eth_num == 1) {
+			if (!eth_getenv_enetaddr("eth1addr", enetaddr))
 				continue;
-			}
-			break;
+		} else
 #endif
-		}
+			if (!eth_getenv_enetaddr("ethaddr", enetaddr))
+				continue;
 
 		/* Allocate device structure */
 		dev = (struct eth_device *)malloc(sizeof(*dev));
@@ -603,22 +597,14 @@
 		}
 		memset(p_npe, 0, sizeof(struct npe));
 
-		switch (eth_num) {
-		default:		/* fall through */
-		case 0:
-			memcpy(dev->enetaddr, bis->bi_enetaddr, 6);
-			p_npe->eth_id = 0;
-			p_npe->phy_no = CONFIG_PHY_ADDR;
-			break;
-
+		p_npe->eth_id = eth_num;
+		memcpy(dev->enetaddr, enetaddr, 6);
 #ifdef CONFIG_HAS_ETH1
-		case 1:
-			memcpy(dev->enetaddr, bis->bi_enet1addr, 6);
-			p_npe->eth_id = 1;
+		if (eth_num == 1)
 			p_npe->phy_no = CONFIG_PHY1_ADDR;
-			break;
+		else
 #endif
-		}
+			p_npe->phy_no = CONFIG_PHY_ADDR;
 
 		sprintf(dev->name, "NPE%d", eth_num);
 		dev->priv = (void *)p_npe;