tf-m-coverity.yaml: bump coverity version to 2020.09

Besides bumping the version from 2019.03 to 2020.09, a new parameter
is introduced, COVERITY_VERSION, indicating the coverity version, this
way, the version is not hardcoded into the builder's shell script.

This patch fixes recent failues (37-44) at [1]. Tested at staging at [2]

[1] https://ci.trustedfirmware.org/job/tf-m-coverity/
[2] https://ci.staging.trustedfirmware.org/job/lsandov1-tf-m-coverity/75/console

Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
Change-Id: I735f535856ca5629f3e45385a09e98a3e56e66cb
1 file changed