Add memorymap to nrf52840 devices only

Author: furbrain

ports/nrf/mpconfigport.mk

@@ -46,7 +46,6 @@ CIRCUITPY_BLE_FILE_SERVICE ?= 1
 CIRCUITPY_SERIAL_BLE ?= 1
 
 CIRCUITPY_COMPUTED_GOTO_SAVE_SPACE ?= 1
-CIRCUITPY_MEMORYMAP ?= 1
 
 
 # nRF52840-specific
@@ -58,6 +57,7 @@ MCU_SUB_VARIANT = nrf52840
 
 # Fits on nrf52840 but space is tight on nrf52833.
 CIRCUITPY_AESIO ?= 1
+CIRCUITPY_MEMORYMAP ?= 1
 
 CIRCUITPY_RGBMATRIX ?= 1
 CIRCUITPY_FRAMEBUFFERIO ?= 1