common: Adding the CpuQos entity

Adding a Cpu Qos entity that will be used by the cpu profile.
the cpu profile will be used to set cpu sla parameters of the vm.

Change-Id: I2134a778d70b3c9ff3e78cc38282a515250b7cf2
Bug-Url: https://bugzilla.redhat.com/1084930
Signed-off-by: Gilad Chaplik <gchaplik@redhat.com>