basesdk: Fix build, depend on devroot

Just like the full SDK, the base SDK image ships the `armhf` devroot
out-of-the-box, so it needs to depend on it.

Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

Jenkinsfile

@@ -69,6 +69,10 @@ def architectures = [
                 image: true,
                 sysroot: false,
                 ostree: false,
+                requires: [
+                    armhf: 'devroot',
+                ]
+
             ]
         ]
     ],