Update CHANGELOG-EE for 7.12 patch releases

CHANGELOG-EE

 v 7.13 (Unrelease)
   - Fix git hook validation on initial push to master branch.
 
-v 7.12
+v 7.12.2
+  - Fixed the alignment of project settings icons
+
+v 7.12.1
+  - No changes specific to EE
+
+v 7.12.0
   - Fix error when viewing merge request with a commit that includes "Closes #<issue id>".
   - Enhance LDAP group synchronization to check also for member attributes that only contain "uid=<username>"
   - Enhance LDAP group synchronization to check also for submember attributes