tests: flash: Enable test on stm32n6570_dk

Since no internal flash is available, provide the right configuration
so the test can run on external flash for stm32n6570_dk.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

tests/drivers/flash/common/Kconfig

@@ -8,7 +8,8 @@ DT_CHOSEN_Z_FLASH := zephyr,flash
 
 config TEST_DRIVER_FLASH_SIZE
 	int "Size of flash device under test"
-	default $(dt_chosen_reg_size_int,$(DT_CHOSEN_Z_FLASH),0) if SOC_FAMILY_STM32
+	default $(dt_chosen_reg_size_int,$(DT_CHOSEN_Z_FLASH),0) \
+		if (SOC_FAMILY_STM32 && !SOC_SERIES_STM32N6X)
 	default -1
 	help
 	  Expected flash device size the test will validate against. If the flash driver does not

tests/drivers/flash/common/boards/stm32n6570_dk_stm32n657xx_sb.conf

@@ -0,0 +1 @@
+CONFIG_TEST_DRIVER_FLASH_SIZE=134217728

tests/drivers/flash/common/src/main.c

@@ -12,6 +12,8 @@
 
 #if defined(CONFIG_NORDIC_QSPI_NOR)
 #define TEST_AREA_DEV_NODE	DT_INST(0, nordic_qspi_nor)
+#elif defined(SOC_SERIES_STM32N6X)
+#define TEST_AREA_DEV_NODE	DT_INST(0, st_stm32_xspi_nor)
 #elif defined(CONFIG_FLASH_RENESAS_RA_OSPI_B)
 #define TEST_AREA_DEV_NODE	DT_INST(0, renesas_ra_ospi_b_nor)
 #elif defined(CONFIG_SPI_NOR)
@@ -26,6 +28,7 @@
  * fixed-partition nodes.
  */
 #ifdef TEST_AREA
+
 #define TEST_AREA_OFFSET	FIXED_PARTITION_OFFSET(TEST_AREA)
 #define TEST_AREA_SIZE		FIXED_PARTITION_SIZE(TEST_AREA)
 #define TEST_AREA_MAX		(TEST_AREA_OFFSET + TEST_AREA_SIZE)