tf-m-build-config: Update TARGET_PLATFORM and PROJ_CONFIG params

Rename TARGET_PLATFORM -> TFM_PLATFORM, remove unused PROJ_CONFIG. These
changes were done long ago on the tf-m-scripts side:
https://git.trustedfirmware.org/ci/tf-m-ci-scripts.git/commit/?id=b708f576db8dedaa1286d4bb23956b390f6a8a8a
, but never were propagated to Jenkins job params. This disallows to
rebuild an existing tf-m-build-config build or start one from scratch.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: Idd13f50989df1ba75cda7092de94af742470a6f9
1 file changed