[ssci] Uplift subzero/bloat third party metadata

This CL modifies the package separator line to the dependency divider
line, so that tools which parse README.chromium files are able to
distinguish between different packages' metadata within a single
README.chromium file.

Change-Id: I9124de65361bdb4a1bcb3a19f5ca0c49ae8715f9
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/72368
Commit-Queue: Shahbaz Youssefi <syoussefi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@google.com>
Tested-by: Shahbaz Youssefi <syoussefi@google.com>
diff --git a/third_party/subzero/bloat/README.chromium b/third_party/subzero/bloat/README.chromium
index f7f6d14..8604f2a 100644
--- a/third_party/subzero/bloat/README.chromium
+++ b/third_party/subzero/bloat/README.chromium
@@ -14,7 +14,7 @@
 Local Modifications:
 Only bloat.py is used (with no modifications).
 
-========================================================================
+-------------------- DEPENDENCY DIVIDER --------------------
 
 Name: Webtreemap - Web-based treemap
 Short Name: webtreemap