Update the format script to use absolute path for clang-format-diff.py
instead of relative path. This ensures the script works correctly
regardless of the current working directory when executed.
- Change from './clang-format-diff.py' to '${root}/projects/rocr-runtime/clang-format-diff.py'
- Improves script reliability and portability
Signed-off-by: Honglei Huang <honghuan@amd.com>