'bootz' expects gziped kernel image anyway, so hard-code it to zImage,
and remove root path from 'load' commands, by default the files are
searched in root directory.
This will make the bootscript static, so the command which modified it
when image was created can now be removed.
Signed-off-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Don't hard-code the PTUUID, use U-Boot commands to determine it, as some
partitioning tools could rewrite PTUUID when modifying partitions.
Signed-off-by: Tomasz Maciej Nowak <tmn505@gmail.com>