Fix build script usage of copied profile file

[greenbreakfast]

What

The add_files function in build.sh currently adds the profile and build.sh script to the cloned u-boot repo.
It's likely when bash /u-boot-wrapper/build.sh build_uboot is run in the docker container, that the /u-boot-wrapper/build.sh script uses the profile file at /u-boot-wrapper/u-boot/profile and not the profile file at /u-boot-wrapper/profile

Resolution

1. Confirm the above is the case
2. Come up with a different method so that the build script can be called A) with an absolute path, and B) when in the u-boot-wrapper directory while still using the profile in the u-boot-wrapper directory