mimxrt/boards/MIMXRT1064_EVK: Fix board config to use internal flash.

This commit is necessary to make MicroPython work on this eval kit out of
the box, as the eval kit ships with the HyperFlash physically disconnected
from the bus (refer to the schematics or the user guide) and the QSPI
connected instead, but the fuses/board/pins are configured to boot from
internal flash (on FlexSPI2).

Note that enabling the HyperFlash is not trivial, as it requires soldering
and desoldering of many small footprint resistors and changing fuses.

ports/mimxrt/boards/MIMXRT1064_EVK/mpconfigboard.mk

@@ -3,8 +3,8 @@ MCU_VARIANT = MIMXRT1064DVL6A
 
 MICROPY_FLOAT_IMPL = double
 MICROPY_PY_MACHINE_SDCARD = 1
-MICROPY_HW_FLASH_TYPE = qspi_hyper_flash
-MICROPY_HW_FLASH_SIZE = 0x4000000  # 64MB
+MICROPY_HW_FLASH_TYPE = internal
+MICROPY_HW_FLASH_SIZE = 0x400000  # 4MB
 
 MICROPY_HW_SDRAM_AVAIL = 1
 MICROPY_HW_SDRAM_SIZE  = 0x2000000  # 32MB