feat(stm32_gpio): add a function to reset a pin

Add set_gpio_reset_cfg() to set a pin in its reset configuration:
analog, no-pull, speed low, and its secure configuration, thanks to
stm32_gpio_is_secure_at_reset().

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: I7b73c3636859f97fcc57f81cf68b42efc727922e
diff --git a/include/drivers/st/stm32_gpio.h b/include/drivers/st/stm32_gpio.h
index e241f58..b072345 100644
--- a/include/drivers/st/stm32_gpio.h
+++ b/include/drivers/st/stm32_gpio.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
  */
@@ -52,6 +52,7 @@
 void set_gpio(uint32_t bank, uint32_t pin, uint32_t mode, uint32_t speed,
 	      uint32_t pull, uint32_t alternate, uint8_t status);
 void set_gpio_secure_cfg(uint32_t bank, uint32_t pin, bool secure);
+void set_gpio_reset_cfg(uint32_t bank, uint32_t pin);
 #endif /*__ASSEMBLER__*/
 
 #endif /* STM32_GPIO_H */