jsonrpc: VM_setCpuTuneQuota

Align naming between API.py and schema.

Change-Id: I397d12419ff1e108c57ad6098f7ca1be5ef44711
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
Reviewed-on: http://gerrit.ovirt.org/35553
Reviewed-by: Oved Ourfali <oourfali@redhat.com>
Reviewed-by: Martin Sivák <msivak@redhat.com>
Reviewed-by: Francesco Romani <fromani@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>