Document 'viridian' hypervisor parameter
Document 'viridian' hypervisor parameter

List the 'viridian' hypervisor parameter (valid for Xen HVM) in the
gnt-instance manpage.

Signed-off-by: Thomas Thrainer <98bdeac947eb8ca18146e9ce7f092788ec242cd1@google.com>
Reviewed-by: Helga Velroyen <2d0126b1ec6f9ec5cbec4a7012aa14faeaef10f5@google.com>

dimara/ganeti,andir/ganeti,yiannist/ganeti,ganeti/ganeti,apyrgio/ganeti,mbakke/ganeti,onponomarev/ganeti,leshchevds/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,bitemyapp/ganeti,andir/ganeti,ganeti/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti,bitemyapp/ganeti,onponomarev/ganeti,leshchevds/ganeti,leshchevds/ganeti,apyrgio/snf-ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,andir/ganeti,dimara/ganeti,grnet/snf-ganeti,grnet/snf-ganeti,mbakke/ganeti,apyrgio/ganeti,mbakke/ganeti