Correct documentation references to Mbed TLS

Use the correct formatting of the product name in the documentation.

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 21f0c77..3a4189d 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -28,7 +28,7 @@
  * This is an optional version symbol that enables comatibility handling of
  * config files.
  *
- * It is equal to the #MBEDTLS_VERSION_NUMBER of the mbedtls version that
+ * It is equal to the #MBEDTLS_VERSION_NUMBER of the Mbed TLS version that
  * introduced the config format we want to be compatible with.
  */
 //#define MBEDTLS_CONFIG_VERSION 0x03000000