stm32: Add initial support for stm32h7

Signed-off-by: Konstantin Vogel <konstantin.vogel@gmx.net>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/stm32/watchdog.c

@@ -4,9 +4,14 @@
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
+#include "autoconf.h" // CONFIG_MACH_STM32H7
 #include "internal.h" // IWDG
 #include "sched.h" // DECL_TASK
 
+#if CONFIG_MACH_STM32H7 // stm32h7 libraries only define IWDG1 and IWDG2
+#define IWDG IWDG1
+#endif
+
 void
 watchdog_reset(void)
 {