src/Makefile: Add header files as dependency

When the header files are modified, the compiled objects are not going
to be recompiled because the header files are not marked as a dependency
for the objects.

  - Instruct the compiler to generate dependency files.

  - Include those files from src/Makefile. Ensure if any changes are
    made, files that depend on the changes are recompiled.

Suggested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Link: https://lore.kernel.org/r/20220310111231.1713588-3-alviro.iskandar@gnuweeb.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2 files changed