samples: drivers: quadspi flash of the stm32 boards

This enables the samples/drivers/spi_flash on quad-spi flash
to run on any stm32 target with external NOR quad flash.
The SPI_FLASH_MULTI_SECTOR_TEST test case is possible with
quadspi too.

Signed-off-by: Francois Ramu <[email protected]>

Author: FRASTM

samples/drivers/spi_flash/src/main.c

@@ -26,7 +26,7 @@
 #endif
 #define SPI_FLASH_SECTOR_SIZE        4096
 
-#if defined CONFIG_FLASH_STM32_OSPI
+#if defined(CONFIG_FLASH_STM32_OSPI) || defined(CONFIG_FLASH_STM32_QSPI)
 #define SPI_FLASH_MULTI_SECTOR_TEST
 #endif