tests: Treat PSA_WANT_ECC_* as manual dependencies

For the time being, it is not possible to determine
the size of ECC keys from the arguments of all test
cases thus treat them as dependencies that are not
systematic. Such dependencies are not generated nor
deleted by set_psa_test_dependencies.py.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/scripts/set_psa_test_dependencies.py b/tests/scripts/set_psa_test_dependencies.py
index e37ce3d..ad1bc90 100755
--- a/tests/scripts/set_psa_test_dependencies.py
+++ b/tests/scripts/set_psa_test_dependencies.py
@@ -105,6 +105,8 @@
 
 def is_systematic_dependency(dep):
     """Whether dep is a PSA dependency which is determined systematically."""
+    if dep.startswith('PSA_WANT_ECC_'):
+        return False
     return dep.startswith('PSA_WANT_')
 
 WITHOUT_SYSTEMATIC_DEPENDENCIES = frozenset([