add missing config file for seccomp

target/linux/config/Config.in.security

@@ -0,0 +1,8 @@
+# This file is part of the OpenADK project. OpenADK is copyrighted
+# material, please see the LICENCE file in the top-level directory.
+
+config ADK_LINUX_KERNEL_SECCOMP
+	bool
+
+config ADK_LINUX_KERNEL_SECCOMP_FILTER
+	bool