layout.conf: add eclass-overlay

BUG=b:264959615
TEST=None

Change-Id: I9cd06026d3c69210958ca316100c8ed3ea234f3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/toolchains/+/4387574
Commit-Queue: Sergey Frolov <sfrolov@google.com>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Sergey Frolov <sfrolov@google.com>
diff --git a/metadata/layout.conf b/metadata/layout.conf
index 4a7f101..27f9175 100644
--- a/metadata/layout.conf
+++ b/metadata/layout.conf
@@ -1,5 +1,5 @@
 cache-format = md5-dict
-masters = portage-stable chromiumos
+masters = portage-stable eclass-overlay chromiumos
 profile-formats = portage-2 profile-default-eapi
 profile_eapi_when_unspecified = 5-progress
 repo-name = toolchains