Allow disabling authentication dynamically

This patch allows platforms to dynamically disable authentication of
images during cold boot. This capability is controlled via the
DYN_DISABLE_AUTH build flag and is only meant for development
purposes.

Change-Id: Ia3df8f898824319bb76d5cc855b5ad6c3d227260
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 4bbff03..cea8533 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -58,6 +58,10 @@
 # Build platform
 DEFAULT_PLAT			:= fvp
 
+# Enable capability to disable authentication dynamically. Only meant for
+# development platforms.
+DYN_DISABLE_AUTH		:= 0
+
 # Flag to enable Performance Measurement Framework
 ENABLE_PMF			:= 0