add arm64 link (#5575)

Author: sirutBuasai

vllm/CHANGELOG.md

@@ -1,6 +1,9 @@
 # Changelog
 
-Available in Amazon ECR Public Gallery: https://gallery.ecr.aws/deep-learning-containers/vllm.
+Available in Amazon ECR Public Gallery:
+
+- https://gallery.ecr.aws/deep-learning-containers/vllm for x86 architecture.
+- https://gallery.ecr.aws/deep-learning-containers/vllm-arm64 for ARM64 architecture.
 
 All notable changes to vLLM Deep Learning Containers will be documented in this file.