CDK: update compatibility matrix

CDK Validium -Node for Fork ID 9 was updated from 0.6.4-CDK to 0.6.4-CDK.2

Author: hsutaiyu

docs/cdk/version-matrix.md

@@ -25,7 +25,7 @@ The table below shows the version compatibility for CDK releases and related com
     <td>CDK Elderberry 2 Release </td>
     <td>9</td>
     <td><a href="https://github.com/0xPolygonHermez/zkevm-node/releases/tag/v0.6.4">v0.6.4 Elderberry 2</a></td>
-    <td><a href="https://hub.docker.com/layers/0xpolygon/cdk-validium-node/0.6.4-cdk/images/sha256-6393eebf06fae415549070001d118aeb886777e532858777ab52096b3c25e5f2?context=explore">0.6.4-cdk</a> </td>
+    <td><a href="https://hub.docker.com/layers/0xpolygon/cdk-validium-node/0.6.4-cdk/images/sha256-6393eebf06fae415549070001d118aeb886777e532858777ab52096b3c25e5f2?context=explore">0.6.4-cdk.2</a> </td>
     <td><a href="https://hub.docker.com/layers/0xpolygon/cdk-data-availability/0.0.7/images/sha256-17590789a831259d7a07d8a042ea87e381c5708dec3a7daef6f3f782f50b2c00?context=explore">v0.0.7</a></td>
     <td><a href="https://github.com/0xPolygonHermez/zkevm-prover/releases/tag/v6.0.0">v6.0.0</a></td>
     <td> <a href="https://github.com/0xPolygonHermez/zkevm-contracts/releases/tag/v5.0.1-rc.2-fork.8">v5.0.1</a></td>