Habana CompiledFunction should be stateless

[gcatron]

With the addition of DeviceBindings to the ExecutionContext the Habana compiledFunction should be refactored to be stateless. This way the same compiledFunction can be run on multiple cards. Once this is done we can close #1951 .

[bertmaher]

What state needs to be removed, exactly? There's ctx_ (which is unused), but the rest is not mutated during execute()

[bertmaher]

Double checking, HabanaFunction is good to go. It doesn't contain any device-specific or mutable state.