32475ce98c
Instead of counting words in make, which is slightly awful, notice that possible_devices is local to external_flash.c, so we can declare the array with an automatic bound, and then get the count as the element-count (MP_ARRAY_SIZE) of the array. Since EXTERNAL_FLASH_DEVICE_COUNT is no longer a global macro, switch a few sites to using EXTERNAL_FLASH_DEVICES in `#if` checks instead.