Update CHANGELOG.md

Update CHANGELOG for ROCm5.6 release

[ROCm/rocm-core commit: fcafd602e3]

projects/rocm-core/CHANGELOG.md

@@ -1,5 +1,8 @@
 Change Logs for rocm-core
+ROCm5.6.0 release
+ - Added initial support for Adress Sanitizer(ASAN) enabled builds.
+ - Full support of ASAN will be coming in later release
 
-Unreleased for ROCm5.5.0
+ROCm5.5.0 release
  - Added module file support for ROCm.
  - From ROCm5.5.0 release ROCm module files can be loaded as rocm/5.5.0