Fix full config in config.py

By default, the full configuration enables all options. But we
specifically don't want to enable MBEDTLS_ECP_WITH_MPI_UINT except where
it's done explicitly, because it disables the old ecp. So it needs to be
added to the exceptions in config.py (EXCLUDE_FROM_FULL).

Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/scripts/config.py b/scripts/config.py
index 3e957fd..cb42c11 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -217,7 +217,8 @@
     'MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND', # build dependency (valgrind headers)
     'MBEDTLS_X509_REMOVE_INFO', # removes a feature
     'MBEDTLS_SSL_RECORD_SIZE_LIMIT', # in development, currently breaks other tests
-    'MBEDTLS_P256M_EXAMPLE_DRIVER_ENABLED' # influences SECP256R1 KeyGen/ECDH/ECDSA
+    'MBEDTLS_P256M_EXAMPLE_DRIVER_ENABLED', # influences SECP256R1 KeyGen/ECDH/ECDSA
+    'MBEDTLS_ECP_WITH_MPI_UINT' # disables the default ECP and is experimental
 ])
 
 def is_seamless_alt(name):