drivers/net/*.c: Use static const

Using static const generally increases object text and decreases data size.
It also generally decreases overall object size.

Signed-off-by: Joe Perches <joe@perches.com>
diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index 50815fb..c149e48 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -1191,7 +1191,7 @@
 
 static void genesis_reset(struct skge_hw *hw, int port)
 {
-	const u8 zero[8]  = { 0 };
+	static const u8 zero[8]  = { 0 };
 	u32 reg;
 
 	skge_write8(hw, SK_REG(port, GMAC_IRQ_MSK), 0);
@@ -1557,7 +1557,7 @@
 	int jumbo = hw->dev[port]->mtu > ETH_DATA_LEN;
 	int i;
 	u32 r;
-	const u8 zero[6]  = { 0 };
+	static const u8 zero[6]  = { 0 };
 
 	for (i = 0; i < 10; i++) {
 		skge_write16(hw, SK_REG(port, TX_MFF_CTRL1),