TZ applications can be secure-only (#204)

<?xml version="1.0" encoding="UTF-8"?>

<package schemaVersion="1.7.36" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="https://raw.githubusercontent.com/Open-CMSIS-Pack/Open-CMSIS-Pack-Spec/v1.7.36/schema/PACK.xsd">

<package schemaVersion="1.7.40" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="https://raw.githubusercontent.com/Open-CMSIS-Pack/Open-CMSIS-Pack-Spec/v1.7.40/schema/PACK.xsd">

  <name>CMSIS</name>

  <description overview="./CMSIS/Documentation/Overview.md">CMSIS (Common Microcontroller Software Interface Standard)</description>

  <vendor>ARM</vendor>

    <condition id="TZ Secure">

      <description>TrustZone (Secure)</description>

      <require Dtz="TZ"/>

      <require Dsecure="Secure"/>

      <accept Dsecure="Secure"/>

      <accept Dsecure="Secure-only"/>

    </condition>

    <!-- OS Tick -->