[dvsim tool] "use_cfgs" usecase enhancement

- expanded "use_cfgs" to list hjson file targets or complete hjson dicts
inline
- this will allow specification of simpler, repeatitive cfgs such as
lint a lot more concisely

Signed-off-by: Srikrishna Iyer <sriyer@google.com>
diff --git a/util/dvsim/Deploy.py b/util/dvsim/Deploy.py
index 84fb53c..95a4230 100644
--- a/util/dvsim/Deploy.py
+++ b/util/dvsim/Deploy.py
@@ -674,13 +674,13 @@
             except Exception as e:
                 ex_msg = "Failed to parse \"{}\":\n{}".format(
                     self.cov_report_dashboard, str(e))
-                log.fail_msg += ex_msg
+                self.fail_msg += ex_msg
                 log.error(ex_msg)
                 self.status = "F"
 
             if self.cov_results == "":
                 nf_msg = "Coverage summary not found in the reports dashboard!"
-                log.fail_msg += nf_msg
+                self.fail_msg += nf_msg
                 log.error(nf_msg)
                 self.status = "F"