(FACT-703) Add virtualization sub-fact to "processors"

Help ito determine if VTX is enabled on the system with a new sub-fact
of "processors".

New sub-fact: "virtualization"
Return True if VTX is enabled.
Return False if VTX is disabled.

Supports Intel & AMD platforms.

Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>