ci/b2c: allow jobs to select a file in the dtb url

This makes it possible to have a single DTB url serving multiple DUTs,
without paying much of a cost for it.

Signed-off-by: Martin Roukala (né Peres) <martin.roukala@mupuf.org>
Reviewed-by: Eric Engestrom <None>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33162>

.gitlab-ci/b2c/b2c.yml.jinja2.jinja2

@@ -106,4 +106,9 @@ deployment:
 {% if dtb_url %}
     dtb:
       url: '{{ dtb_url }}'
+{% if dtb_match %}
+      format:
+        archive:
+          match: "{{ dtb_match }}"
+{% endif %}
 {% endif %}