shill: EAPListener: Accept EAP version 1 packets

Accept EAP vesrsion 1 packets in addition to EAP version 2 and
greater, in order to allow some authenticators displaying this
version to work.

BUG=chromium:353147
TEST=Unit tests

Change-Id: I364b4093ed2d2b2de99982afe511c57221a4537f
Reviewed-on: https://chromium-review.googlesource.com/198883
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
diff --git a/eap_protocol.h b/eap_protocol.h
index 34cf224..619dbd2 100644
--- a/eap_protocol.h
+++ b/eap_protocol.h
@@ -19,6 +19,7 @@
 };
 
 enum IeeeEapolVersion {
+  kIeee8021xEapolVersion1 = 1,
   kIeee8021xEapolVersion2 = 2
 };