Add support to connect Arm Development Studio IDE to FVP on local runs.

This patch adds the environment variable "connect_debugger" to CI:

     * When connect_debugger == 0 (default), CI will work as usual.
     * When connect_debugger == 1, CI will
       - Call FVP with the -S flag enabled, so it can connect
       	 to ARM DS IDE for debugging sessions.
       - Set test_run variable to 1, overriding any manual
         setting for this variable.
       - Build TF-A with SPIN_ON_BL1 flag enabled.

Change-Id: I300b9babc28c0d4752bf3352ca3599da14f34edb
Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
diff --git a/script/build_package.sh b/script/build_package.sh
index 6a5fe6e..9b8e000 100755
--- a/script/build_package.sh
+++ b/script/build_package.sh
@@ -489,10 +489,14 @@
 
 EOF
 
+	if not_upon "$local_ci"; then
+		connect_debugger=0
+	fi
+
 	# Build TF. Since build output is being directed to the build log, have
 	# descriptor 3 point to the current terminal for build wrappers to vent.
 	$tf_build_wrapper make $make_j_opts $(cat "$config_file") \
-		DEBUG="$DEBUG" V=1 \
+		DEBUG="$DEBUG" V=1 SPIN_ON_BL1_EXIT="$connect_debugger" \
 		$build_targets 3>&1 &>>"$build_log" || fail_build
 	)
 }
@@ -795,6 +799,7 @@
 
 gen_model_params() {
 	local model_param_file="$archive/model_params"
+	[ "$connect_debugger" ] && [ "$connect_debugger" -eq 1 ] && wait_debugger=1
 
 	set_default_bin_paths
 	echo "Generating model parameter for $model..."