[platform]: update to latest arista drivers (#515)

Staphylo · lguohan · commit 68fcc3654986 · 2017-04-18T17:50:31.000-07:00
diff --git a/platform/broadcom/sonic-platform-modules-arista b/platform/broadcom/sonic-platform-modules-arista
@@ -1 +1 @@
-Subproject commit 76dddcf648cec1305eeb0ff4ba00ff234e986fd5
+Subproject commit a1ca8013e952d1cc0d555c24fe6eb2bf016ab694
