include readmes for run, scp adn tftf config folders

Change-Id: I4c4f9c81ca828db3882a70e3338de8ae437b2626
Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
diff --git a/scp_config/README b/scp_config/README
new file mode 100644
index 0000000..c713f42
--- /dev/null
+++ b/scp_config/README
@@ -0,0 +1,8 @@
+#
+# Copyright (c) 2019, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+Files in this directory sets System Control Processor (SCP) build options as
+they ought to appear on the build command line.