TF-M: Add setup-ssh and fix permissions

setup-ssh is required for YADP, also the jar file has never been
readable by the buildslave user. Lets fix this.

Signed-off-by: Benjamin Copeland <ben.copeland@linaro.org>
Change-Id: I2076bb62eefc9c0a09612a0d3e62bfdbc9ef8c37
diff --git a/bionic-amd64-tf-m-build/setup-sshd b/bionic-amd64-tf-m-build/setup-sshd
new file mode 100755
index 0000000..b0a5ed5
--- /dev/null
+++ b/bionic-amd64-tf-m-build/setup-sshd
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+export HOME=/home/buildslave
+
+[ -z "${JENKINS_SLAVE_SSH_PUBKEY}" ] || {
+  mkdir ${HOME}/.ssh
+  echo "${JENKINS_SLAVE_SSH_PUBKEY}" > ${HOME}/.ssh/authorized_keys
+  chown -R buildslave:buildslave ${HOME}/.ssh
+  chmod 0700 -R ${HOME}/.ssh
+}
+
+exec /usr/sbin/sshd -D