Support Minikube for development on Mac arm silicon

[techcobweb]

Story

As a developer of Galasa code with a arm64 Mac, after making a change and building it, I want to deploying to a local minikube so that I can test everything works.

Background

There are 2 things preventing this from working now:

• The Galasa bootloader image doesn't have an arm64 version
• The Etcd image doesn't support arm64 at the current version, needs upgrading.

This will make it far easier to explain how to set up a running system to test with, and give us better testing locally prior to delivering changes to the main branch.