doc,oeqa/cam,yocto: Remove cam-service from Primary Compute

Refine the remit of CAM usage to strictly within the Kronos
design and test area. This includes:
 1. Remove documentation references to running cam-service on
    the Primary Compute.
 2. Remove test cases which invoke cam-service on the Primary
    Compute and any references to them in the documentation.
 3. Remove test cases which only test the CAM utility help
    output and any references to them in the documentation.
 4. Remove cam-service from the Kronos FEATURE_PACKAGES since
    it should not be used on the Primary Compute.

Signed-off-by: Debbie Martin <Debbie.Martin@arm.com>