OOB inspection timeout fix for iDRAC

Make inspection timeout configurable to fix iDRAC driver out of band
inspection intermittent timeout issue for idrac-wsman and idrac-redfish
inspect interface.
For idrac, at least 20 seconds is recommended to be set for inspect
timeout for successful execution of OOB inspection.

Change-Id: Ibdf78d0669d0afb43d32bb71e7710145ffb7c05e
diff --git a/ironic_tempest_plugin/config.py b/ironic_tempest_plugin/config.py
index 6b05402..fd86d47 100644
--- a/ironic_tempest_plugin/config.py
+++ b/ironic_tempest_plugin/config.py
@@ -97,6 +97,9 @@
                default=30,
                help="Timeout for association of Nova instance and Ironic "
                     "node"),
+    cfg.IntOpt('inspect_timeout',
+               default=10,
+               help="Timeout for inspecting an Ironic node."),
     cfg.IntOpt('power_timeout',
                default=60,
                help="Timeout for Ironic power transitions."),