Allow users to specify nicController for KVM VMs

[yadvr]

Like other VM instance properties, add a new property nicController both in template and instance properties to allow users/admins to specify the nic controller of a VM for KVM.

ISSUE TYPE

• Feature Idea

COMPONENT NAME

KVM, template, VM

[yadvr]

@Pearl1594 has advised nicAdapter vm/template property can be used, and works from API but not UI.