Jenkinsfile: poll the linux branch for changes

Jenkinsfile

+properties([
+    pipelineTriggers([
+        [$class: "SCMTrigger", scmpoll_spec: "* * * * *"],
+    ])
+])
+
 node {
     gitUrl = 'https://source.puri.sm/librem5/kernel-builder.git'
     artifacts = 'output/*'
@@ -14,7 +20,7 @@ node {
     }
 
     stage('Setup') {
-        git url: gitUrl, branch: branch
+        git poll: true, url: gitUrl, branch: branch
     }
     stage('Build kernel') {
         sh "KERNEL_REPO=${kernel_url} KERNEL_BRANCH=${kernel_branch} MAKE_OPTS=${MAKE_OPTS} DOT_CONFIG=${dot_config} ./build_kernel_deb.sh -b ${board}"