fix(stm32mp1): do not reopen debug features

On closed chips, it is not allowed to open debug. The BSEC debug
register can not be rewritten.
On open chips, the debug is already open, no need to rewrite this
register. This part of code is just removed.
An INFO message is displayed if debug is disabled.
The freeze of the watchdog during debug is also removed.
In case of debug, this must be managed by the software that enables
the debugger.

Change-Id: I19fbd3c487bb1018db30fd599cfa94fe5090899f
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
diff --git a/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h b/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h
index 498a4f2..3663bce 100644
--- a/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h
+++ b/plat/st/stm32mp1/include/stm32mp1_dbgmcu.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2019, STMicroelectronics - All Rights Reserved
+ * Copyright (c) 2015-2021, STMicroelectronics - All Rights Reserved
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -13,11 +13,4 @@
 int stm32mp1_dbgmcu_get_chip_version(uint32_t *chip_version);
 int stm32mp1_dbgmcu_get_chip_dev_id(uint32_t *chip_dev_id);
 
-/*
- * Freeze watchdog when a debugger is attached, if the security configuration
- * allows it.
- * Return 0 on success, a negative error value otherwise.
- */
-int stm32mp1_dbgmcu_freeze_iwdg2(void);
-
 #endif /* STM32MP1_DBGMCU_H */