Devices using the MCUX FlexSPI flash driver erase their flash too
slowly, causing the usb stack to freeze, and USB DFU utilities to
report a timeout. Enable IMG_ERASE_PROGRESSIVELY for SOCs using the
MCUX FlexSPI driver to prevent this error.
Fixes#45359
Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>