update u-boot,linux kernel to compile dtb and zImage into single idb file; ...

guowenxue

2019-08-23 9393cb81acc34d1bd27cc921d8d98e618fb74662

tools/buildroot-2019.02-gcc7.4.0-cortexA5-x86_64_arm-linux-gnueabihf.tar.xz does not exist in tree 3faaad6cd0f108f36edcf9be7b93079f5a5b8cff