soc: st: stm32: stm32h7rsx: enable special_region to fix access violation

Adds an MPU region named SPECIAL_REGION at address
0x08FFF800 with a size of 2 KB in Flash memory.

The region was previously unprotected, leading to an MPU fault when
accessed. By marking it as executable and readable with appropriate
flash memory attributes, the test now completes without triggering
a fault.

This change resolves a data Access Violation observed during
multiple tests, where the faulting address was 0x08FFF808.

Signed-off-by: Fabrice DJIATSA <[email protected]>

Author: djiatsaf-st

soc/st/stm32/stm32h7rsx/mpu_regions.c

@@ -26,6 +26,9 @@ static const struct arm_mpu_region mpu_regions[] = {
 
 	/* Region 3 */
 	MPU_REGION_ENTRY("SRAM_0", CONFIG_SRAM_BASE_ADDRESS, REGION_RAM_ATTR(REGION_SRAM_SIZE)),
+
+	/* Special region */
+	MPU_REGION_ENTRY("SPECIAL_REGION", 0x08fff800, REGION_FLASH_ATTR(REGION_2K)),
 };
 
 const struct arm_mpu_config mpu_config = {