tf-a-lts2.8-main: Revert tf-l2-boot-tests-partner-boards switchover

Revert part of I279a1c7bbf577fca41bff3517eab680cd037f3a9 related to
lts-v2.8 branch, as that branch doesn't have such a test group. Just
revert it for now to recover CI builds, if enablement for 2.8 is
required, that should be a separate task.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: Ic938c715b1e734ad020be6fbaecc4ca4a74f9625
diff --git a/tf-a-lts2.8-main.yaml b/tf-a-lts2.8-main.yaml
index 5e01720..fe33c8b 100644
--- a/tf-a-lts2.8-main.yaml
+++ b/tf-a-lts2.8-main.yaml
@@ -276,10 +276,10 @@
           predefined-parameters: TEST_GROUPS=spm-l3-boot-tests
           property-file: tf-a-env.param
         - name: tf-a-lts2.8-ci-gateway
-          alias: tf-l2-boot-tests-partner-boards
+          alias: tf-l1-boot-tests-plat
           current-parameters: true
           kill-phase-on: NEVER
-          predefined-parameters: TEST_GROUPS=tf-l2-boot-tests-partner-boards
+          predefined-parameters: TEST_GROUPS=tf-l1-boot-tests-plat
           property-file: tf-a-env.param
     - multijob:
         name: Run doc build check