One way of deploying Windows Server virtual machines in Azure using the Azure Hybrid Use Benefit is to use a Marketplace image.
This is where you can find the available Bring Your Own Licence (BYOL) images and choose your ideal virtual machine configuration: http://bit.ly/2pLqPKo.
Microsoft announce a new set of Bring-Your-Own-Licence SQL + Windows virtual machine images in the Azure Gallery.
This means that you can use an image to easily provision a Windows VM with SQL Server, and then use existing Volume Licensing licences with Software Assurance to license the SQL part of the VM.
For more details and some useful pictures, see the Microsoft announcement here: http://bit.ly/1Uf54zu.