nfit_test: Enable DSMs for all test NFITs

In preparation for getting a poison list using ARS DSMs, enable DSMs for
all manufactured NFITs supplied by the test framework.  Also, supply
valid response data for ars_status.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>