Moved the MbedTLS config adjust headers to a private subdirectory

Signed-off-by: Anton Matkin <anton.matkin@arm.com>
diff --git a/include/mbedtls/private/config_adjust_x509.h b/include/mbedtls/private/config_adjust_x509.h
new file mode 100644
index 0000000..4af9766
--- /dev/null
+++ b/include/mbedtls/private/config_adjust_x509.h
@@ -0,0 +1,35 @@
+/**
+ * \file mbedtls/private/config_adjust_x509.h
+ * \brief Adjust X.509 configuration
+ *
+ * This is an internal header. Do not include it directly.
+ *
+ * Automatically enable certain dependencies. Generally, MBEDTLS_xxx
+ * configurations need to be explicitly enabled by the user: enabling
+ * MBEDTLS_xxx_A but not MBEDTLS_xxx_B when A requires B results in a
+ * compilation error. However, we do automatically enable certain options
+ * in some circumstances. One case is if MBEDTLS_xxx_B is an internal option
+ * used to identify parts of a module that are used by other module, and we
+ * don't want to make the symbol MBEDTLS_xxx_B part of the public API.
+ * Another case is if A didn't depend on B in earlier versions, and we
+ * want to use B in A but we need to preserve backward compatibility with
+ * configurations that explicitly activate MBEDTLS_xxx_A but not
+ * MBEDTLS_xxx_B.
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
+#ifndef MBEDTLS_CONFIG_ADJUST_X509_H
+#define MBEDTLS_CONFIG_ADJUST_X509_H
+
+#if !defined(MBEDTLS_CONFIG_FILES_READ)
+#error "Do not include mbedtls/config_adjust_*.h manually! This can lead to problems, " \
+    "up to and including runtime errors such as buffer overflows. " \
+    "If you're trying to fix a complaint from check_config.h, just remove " \
+    "it from your configuration file: since Mbed TLS 3.0, it is included " \
+    "automatically at the right point."
+#endif /* */
+
+#endif /* MBEDTLS_CONFIG_ADJUST_X509_H */