tf-a-gerrit-tforg-l1: Add explicit params SPM_REFSPEC, CI_REFSPEC, MBEDTLS_URL

These parameters vary between mainline vs LTS releases, and to have
consistent maintainable jobs, these parameters should be consistently
available.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I4649acf70dc10505d8b6a0653b5dba5077a1f2c8
1 file changed