examples/vm_power: cli in host

examples/vm_power: cli in host

The CLI is used for administrating the channel monitor and manager and
manually setting the CPU frequency on the host.

Supports the following commands:
 add_vm [Mul-choice STRING]: add_vm|rm_vm <name>, add a VM for subsequent
  operations with the CLI or remove a previously added VM from the VM Power
  Manager

 rm_vm [Mul-choice STRING]: add_vm|rm_vm <name>, add a VM for subsequent
  operations with the CLI or remove a previously added VM from the VM Power
  Manager

 add_channels [Fixed STRING]: add_channels <vm_name> <list>|all, add
  communication channels for the specified VM, the virtio channels must be
  enabled in the VM configuration(qemu/libvirt) and the associated VM must be
  active. <list> is a comma-separated list of channel numbers to add, using the
  keyword 'all' will attempt to add all channels for the VM

 set_channel_status [Fixed STRING]:
  set_channel_status <vm_name> <list>|all enabled|disabled,  enable or disable
  the communication channels in list(comma-separated) for the specified VM,
  alternatively list can be replaced with keyword 'all'. Disabled channels will
  still receive packets on the host, however the commands they specify will be
  ignored. Set status to 'enabled' to begin processing requests again.

 show_vm [Fixed STRING]: show_vm <vm_name>, prints the information on the
  specified VM(s), the information lists the number of vCPUS, the pinning to
  pCPU(s) as a bit mask, along with any communication channels associated with
  each VM

 show_cpu_freq_mask [Fixed STRING]: show_cpu_freq_mask <mask>, Get the current
  frequency for each core specified in the mask

 set_cpu_freq_mask [Fixed STRING]: set_cpu_freq <core_mask> <up|down|min|max>,
  Set the current frequency for the cores specified in <core_mask> by scaling
  each up/down/min/max.

 show_cpu_freq [Fixed STRING]: Get the current frequency for the specified core

 set_cpu_freq [Fixed STRING]: set_cpu_freq <core_num> <up|down|min|max>,
  Set the current frequency for the specified core by scaling up/down/min/max

 quit [Fixed STRING]: close the application

Signed-off-by: Alan Carew <alan.carew@intel.com>
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>