mkcloud: make hyperv_node_memory parametrizable
mkcloud: make hyperv_node_memory parametrizable

This makes it consistent with the other memory variables.

aspiers/automation,vmoravec/automation,SUSE-Cloud/automation,aspiers/automation,vmoravec/automation,gosipyan/automation,vmoravec/automation,gosipyan/automation,aspiers/automation,gosipyan/automation,vmoravec/automation,aspiers/automation,SUSE-Cloud/automation,gosipyan/automation,SUSE-Cloud/automation,SUSE-Cloud/automation