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/r8169.c b/drivers/net/r8169.c
index 4e745af..e165d96 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -2526,7 +2526,7 @@
 
 		val = mdio_read(ioaddr, 0x0d);
 		if ((val & 0x00ff) != 0x006c) {
-			u32 set[] = {
+			static const u32 set[] = {
 				0x0065, 0x0066, 0x0067, 0x0068,
 				0x0069, 0x006a, 0x006b, 0x006c
 			};