Add inst_type parameter

Add inst_type parameter in order to generate the bandwidth tag into
the libvirt configuration.

Change-Id: I63c1fb51ea637d461755b309c7464f4b4d49a4b2
Fixes: bug #1185030
(cherry picked from commit 08f8773b9a4fe7fea248b4501230ebd6e6ef2fde)
Merge "Add inst_type parameter" into stable/grizzly