Configure compilation script

The compilation script is Release_to_customer.sh, through which the entire project can be compiled, including uboot, kernel and rootfs. The configuration needs to be modified before running:

• Modify the image save path, the image is saved in the ${RELEASEDIR}/images/ directory;
  #RELEASEDIR=/home/ronnie/work/ssd201/ssd20x_sdk_v008
  
• Modify ARCH to arm
  #export ARCH=arm
  
• 优化编译速度