Merge pull request micropython#8646 from jepler/hallowing-m0-2mb

add another flash chip for hallowing m0 express

Author: dhalbert

ports/atmel-samd/boards/hallowing_m0_express/mpconfigboard.mk

@@ -7,7 +7,7 @@ CHIP_VARIANT = SAMD21G18A
 CHIP_FAMILY = samd21
 
 SPI_FLASH_FILESYSTEM = 1
-EXTERNAL_FLASH_DEVICES = "W25Q64JVxQ, GD25Q64C"
+EXTERNAL_FLASH_DEVICES = "W25Q64JVxQ, GD25Q64C, W25Q16JVxQ"
 LONGINT_IMPL = NONE
 
 # To keep the build small