Fix MK_PIPELINES_REFSPEC parametr for upgrade scenario

Change-Id: Ie4b83d6409b9d4ba83d7a793557887aeedab1e8d
diff --git a/tcp_tests/tests/system/test_mcp_update.py b/tcp_tests/tests/system/test_mcp_update.py
index 1ff1294..c6033c1 100644
--- a/tcp_tests/tests/system/test_mcp_update.py
+++ b/tcp_tests/tests/system/test_mcp_update.py
@@ -237,6 +237,8 @@
         job_name = 'upgrade-mcp-release'
         job_parameters = {
             'GIT_REFSPEC': update_to_tag or 'release/proposed/2019.2.0',
+            'MK_PIPELINES_REFSPEC':
+                update_to_tag or 'release/proposed/2019.2.0',
             'TARGET_MCP_VERSION': update_to_tag or '2019.2.0',
             "DRIVE_TRAIN_PARAMS": {
                         "OS_DIST_UPGRADE": True,