eclair/: ECLAIR configs and scripts

Mostly copied from the TF-A implementation, but with some changes for TF-M
already.

Includes external_sources.ecl, a dedicated file for external
sources specification.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: Ia092024205f0bc2d350318afdc2aed855dedf091
diff --git a/eclair/public_APIs.ecl b/eclair/public_APIs.ecl
new file mode 100644
index 0000000..ec38426
--- /dev/null
+++ b/eclair/public_APIs.ecl
@@ -0,0 +1,5 @@
+# Definition of the public APIs.
+
+
+-doc="FIXME: add proper documentation."
+-file_tag+={api:public,"^interface/include/psa\\.h$"}