engine: VM Device Type for Display Type

* This change added VM Device Type for Display Type in property file.
* The attribute VM Device Type for each OS is present in the os info
  property file.
* The attribute VM Device Type in the Display Type now is the default
  value if none is found in the os file.
* Also the os info attribute spiceSupport was removed, since it would
  be ambiguous. The list now is the OS supported displays.

Change-Id: I326f8aaf0de95332436499205f90336d2f4e73d7
Signed-off-by: Gustavo Pedrosa <gustavo.pedrosa@eldorado.org.br>
Signed-off-by: Leonardo Bianconi <leonardo.bianconi@eldorado.org.br>