utils.sh: tidy up the script

Using "tf-a-<TF-A_LTS_BRANCH>" to change the download space
for the LTS branch

Change-Id: I4d6e7ff1f0ab406ef83e77f4bea4ca8fbdb1e3b8
Signed-off-by: Arthur She <arthur.she@linaro.org>
(cherry picked from commit 2c9ca72a1f20d8ce437943b7e6f0f8c9b987ed09)
diff --git a/utils.sh b/utils.sh
index b830390..9b6310d 100644
--- a/utils.sh
+++ b/utils.sh
@@ -26,13 +26,7 @@
   if echo "$JENKINS_URL" | grep -q "oss.arm.com"; then
     source "$ci_root/arm-env.sh"
   elif echo "$JENKINS_URL" | grep -q "ci.trustedfirmware.org"; then
-    if echo "$TF_GERRIT_BRANCH" | grep -q "lts-v2.8"; then
-      source "$ci_root/openci-lts-v2.8-env.sh"
-    elif echo "$TF_GERRIT_BRANCH" | grep -q "lts-v2.10"; then
-      source "$ci_root/openci-lts-v2.10-env.sh"
-    else
-      source "$ci_root/openci-env.sh"
-    fi
+    source "$ci_root/openci-env.sh"
   elif echo "$JENKINS_URL" | grep -q "ci.staging.trustedfirmware.org"; then
     source "$ci_root/openci-staging-env.sh"
   fi