Merge pull request #2800 from dhalbert/nrf-firmware-size-fix

fix calculation of nrf firmware size

Author: tannewt

ports/nrf/mpconfigport.h

@@ -149,7 +149,7 @@
 #define CIRCUITPY_BLE_CONFIG_START_ADDR (CIRCUITPY_INTERNAL_NVM_START_ADDR - CIRCUITPY_BLE_CONFIG_SIZE)
 
 // The firmware space is the space left over between the fixed lower and upper regions.
-#define CIRCUITPY_FIRMWARE_SIZE (CIRCUITPY_INTERNAL_FLASH_FILESYSTEM_START_ADDR - CIRCUITPY_FIRMWARE_START_ADDR - CIRCUITPY_BLE_CONFIG_SIZE)
+#define CIRCUITPY_FIRMWARE_SIZE (CIRCUITPY_BLE_CONFIG_START_ADDR - CIRCUITPY_FIRMWARE_START_ADDR)
 
 #if BOOTLOADER_START_ADDR % FLASH_ERASE_SIZE != 0
 #error BOOTLOADER_START_ADDR must be on a flash erase boundary.