[bsp][stm32] Add mprotect static region for F407ZGT6

Add a reference implementation of the static MPU region for the
STM32F407ZGT6 BSP, guarded by RT_USING_MEM_PROTECTION so it is not
enabled by default.

- board.h: include rtthread.h and define NUM_STATIC_REGIONS.
- board.c: define static_regions[] marking the Flash region read-only.

Author: Zepp-Hanzj

bsp/stm32/stm32f407-fk407m2-zgt6/board/board.c

@@ -11,6 +11,19 @@
 #include <board.h>
 #include <drv_common.h>
 
+#ifdef RT_USING_MEM_PROTECTION
+#include "mprotect.h"
+
+rt_mem_region_t static_regions[NUM_STATIC_REGIONS] = {
+  /* Flash region, read only */
+  {
+    .start = (void *)STM32_FLASH_START_ADRESS,
+    .size = (rt_size_t)STM32_FLASH_SIZE,
+    .attr = RT_MEM_REGION_P_RX_U_RX,
+  },
+};
+#endif
+
 void SystemClock_Config(void)
 {
   RCC_OscInitTypeDef RCC_OscInitStruct = {0};

bsp/stm32/stm32f407-fk407m2-zgt6/board/board.h

@@ -11,6 +11,7 @@
 #ifndef __BOARD_H__
 #define __BOARD_H__
 
+#include <rtthread.h>
 #include <stm32f4xx.h>
 
 #ifdef __cplusplus
@@ -37,6 +38,10 @@ extern int __bss_end;
 
 #define HEAP_END        STM32_SRAM_END
 
+#ifdef RT_USING_MEM_PROTECTION
+#define NUM_STATIC_REGIONS 1
+#endif
+
 void SystemClock_Config(void);
 
 #ifdef __cplusplus