arm: mpu: Remove FLASH_0 mpu region when XIP=n

When not using CONFIG_XIP (CONFIG_XIP=n)
the FLASH_0 mpu region needs to be removed,
otherwise it will have the default base
address = 0, which means that MPU will try
to configure the region with address 0.
We don't want this as in some situations
address 0 can be a restricted memory region
such as ROM code.

Signed-off-by: Alexandru Lastur <alexandru.lastur@nxp.com>

Author: alxlastur

arch/arm/core/mpu/arm_mpu_regions.c

@@ -10,6 +10,7 @@
 #include <zephyr/arch/arm/cortex_m/arm_mpu_mem_cfg.h>
 
 static const struct arm_mpu_region mpu_regions[] = {
+#ifdef CONFIG_XIP
 	/* Region 0 */
 	MPU_REGION_ENTRY("FLASH_0",
 			 CONFIG_FLASH_BASE_ADDRESS,
@@ -19,6 +20,8 @@ static const struct arm_mpu_region mpu_regions[] = {
 #else
 			 REGION_FLASH_ATTR(REGION_FLASH_SIZE)),
 #endif
+#endif
+
 	/* Region 1 */
 	MPU_REGION_ENTRY("SRAM_0",
 			 CONFIG_SRAM_BASE_ADDRESS,