feat(drivers/st): manage boot part in io_mmc

Use dedicated read function for boot partition

Signed-off-by: Vyacheslav Yurkov <uvv.mail@gmail.com>
Change-Id: If75df7691fce0797205365736fc6e4e3429efdca
diff --git a/include/drivers/st/io_mmc.h b/include/drivers/st/io_mmc.h
index b35b4b5..6179e89 100644
--- a/include/drivers/st/io_mmc.h
+++ b/include/drivers/st/io_mmc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,10 @@
 
 #include <drivers/io/io_driver.h>
 
+struct io_mmc_dev_spec {
+	bool use_boot_part;
+};
+
 int register_io_dev_mmc(const io_dev_connector_t **dev_con);
 
 #endif /* IO_MMC_H */