dm: test: Add a new test case for dm_test_eth_rotate

Add one more ethernet device node in the sandbox test device tree,
with name 'sbe5'. This is to support a new test case for testing
network device rotation.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
index 6965d92..32e3a9b 100644
--- a/include/configs/sandbox.h
+++ b/include/configs/sandbox.h
@@ -187,7 +187,8 @@
 
 #define SANDBOX_ETH_SETTINGS		"ethaddr=00:00:11:22:33:44\0" \
 					"eth1addr=00:00:11:22:33:45\0" \
-					"eth5addr=00:00:11:22:33:46\0" \
+					"eth3addr=00:00:11:22:33:46\0" \
+					"eth5addr=00:00:11:22:33:47\0" \
 					"ipaddr=1.2.3.4\0"
 
 #define MEM_LAYOUT_ENV_SETTINGS \