Refactor and update Makefile

[Prajyot-Parab]

/kind feature
/area provider/ibmcloud

Describe the solution you'd like
A possible set of actions to make this happen using the current machinery in place is to:

• standardise targets names
• standardise targets documentation (e.g all with or without a final dot, consistent wording etc. etc)
• ensure all the make targets are documented/available
• re shuffle make targets order, so that we can group things in sections by adding comments starting with ##@

Anything else you would like to add:
Reference - kubernetes-sigs/cluster-api#5806