testcases: master: template-kselftest: set default revision to '.'

Default the revision to '.' if TDEFINITIONS_REVISION is not set.

Reported-by: Senthil Kumaran S <senthil.kumaran@linaro.org>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>

lava_test_plans/testcases/master/template-kselftest.yaml.jinja2

@@ -37,7 +37,7 @@
 {% for testname in testnames %}
     - repository: {{ TEST_DEFINITIONS_REPOSITORY }}
       from: git
-      revision: '{{ TDEFINITIONS_REVISION }}'
+      revision: '{{ TDEFINITIONS_REVISION|default(.) }}'
       path: automated/linux/kselftest/kselftest.yaml
       name: kselftest-{{testname|replace('.', '-')}}{{vsyscall_suffix}}
       parameters: