Add platform2 fork

BUG=b/465833194
TEST=init and sync

Change-Id: I67cfcc6acdf1f21c9a26fb4eb42e2681405cd20f
Reviewed-on: https://cos-review.googlesource.com/c/cos/manifest/+/120648
Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Reviewed-by: He Gao <hegao@google.com>
diff --git a/external_full.xml b/external_full.xml
index 7adc4c9..f666a27 100644
--- a/external_full.xml
+++ b/external_full.xml
@@ -55,9 +55,6 @@
   <project path="src/third_party/modp_b64"
            name="mirrors/cros/aosp/platform/external/modp_b64"
            revision="68a503fff7af8fbf6f78cd496830813d41150817" />
-  <project path="src/platform2"
-           name="mirrors/cros/chromiumos/platform2"
-           revision="1f610748c54f9ebcca7db2a677b4ca1d24a5de07" />
   <project path="infra_virtualenv"
            name="mirrors/cros/chromiumos/infra_virtualenv"
            revision="649440ce2ab9f7f7c640344c083825eebdc934ee" />
@@ -182,6 +179,9 @@
   <project path="src/platform/vboot_reference"
            name="third_party/platform/vboot_reference"
            revision="refs/heads/release-R121" />
+  <project path="src/platform2"
+           name="third_party/platform2"
+           revision="refs/heads/release-R121" />
   <project path="src/compliance"
            name="cos/compliance"
            revision="refs/heads/main-R121" />