systest: Add syslib/resource.robot for HTX variables

Add syslib/resource.robot include for HTX variables.
This is needed to be able to override test default values with command line variables.

Test:
- Tested by overriding these variables
HTX_DURATION, HTX_INTERVAL, HTX_LOOP, HTX_KEEP_RUNNING, HTX_MDT_PROFILE

Signed-off-by: Peter D  Phan <peterp@us.ibm.com>
Change-Id: I634a99a288cfc98d47fddb87d19ac0f90fb43374
diff --git a/systest/htx_hardbootme_test.robot b/systest/htx_hardbootme_test.robot
index 9a65c53..789a713 100755
--- a/systest/htx_hardbootme_test.robot
+++ b/systest/htx_hardbootme_test.robot
@@ -41,6 +41,7 @@
 Resource        ../lib/logging_utils.robot
 Resource        ../lib/code_update_utils.robot
 Resource        ../lib/esel_utils.robot
+Resource        ../syslib/resource.robot
 Library         ../syslib/utils_keywords.py
 Library         ../lib/utils_files.py
 Library         ../lib/logging_utils.py