Description of problem:

When creating via REST API a vm from an instance type which include custom values for cpu type and emulated machine, the vm is created successfully but without these calues (the value is set back to the default None in DB).
When created via webadmin, the values are inherited as expected.

Version-Release number of selected component (if applicable):
rhevm-4.0.5.4-0.1.el7ev

How reproducible:
always

Steps to Reproduce:
1. create/edit an instance type to include some values for system -> custom emulated machine and custom cpu type.
2. Create a vm using API, create from the instance type from (1).


Actual results:
Vm is created, but the values for custom emulated machine and cpu type is None.

Expected results:
Vm is created with the correct values.

Additional info:
no useful information in engine.log