sandbox: Update the test MAC/IP addresses

These conflict with real-word addresses. Use locally administered
MAC addresses and a suitable IPv4 address from 192.0.2.0/24
(TEST-NET-1).

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Alexander Dahl <ada@thorsis.com>

board/sandbox/sandbox.env

@@ -5,13 +5,13 @@ stdin+=,cros-ec-keyb,usbkbd
 stdout=serial,vidconsole
 stderr=serial,vidconsole
 
-ethaddr=00:00:11:22:33:44
-eth2addr=00:00:11:22:33:48
-eth3addr=00:00:11:22:33:45
-eth4addr=00:00:11:22:33:48
-eth5addr=00:00:11:22:33:46
-eth6addr=00:00:11:22:33:47
-ipaddr=1.2.3.4
+ethaddr=02:00:11:22:33:44
+eth2addr=02:00:11:22:33:48
+eth3addr=02:00:11:22:33:45
+eth4addr=02:00:11:22:33:48
+eth5addr=02:00:11:22:33:46
+eth6addr=02:00:11:22:33:47
+ipaddr=192.0.2.1
 
 /*
  * These are used for distro boot which is not supported. But once bootmethod