1. lpc55s69_dsbl_tools: provide tools to create crc of original image(dsbl_app.bin ->dsbl_app_crc.bin). see readme in lpc55s69_dsbl_tools folder.
2. lpc55s69_dsbl_sdk2.8: MCUX project zip file. contain dsbl and dsbl app source. SDK version must be 2.8.0
