Organize generated include files

[erwango]

Is your enhancement proposal related to a problem? Please describe.
We can generate a lot of include files at build, all under zephyr/include/generated.
We're generating files that belong to various type: header, linker files, ...

It would be nice to have a sublevel folder hierarchy.
Note: there is already a sublevel zephyr/include/generated\syscalls

Describe the solution you'd like
Generate include files under a sublevel category:

generated
 └── include
     ├── linker
     ├── dts
     ├── kernel
     ├── ...
     └── syscalls

Describe alternatives you've considered
Sit down and watch the mess growing

[ulfalizer]

The naming seems a bit redundant at the moment, like zephyr/include/generated/generated_dts_board_fixups.h. I wonder if it could just be zephyr/include/dts_board_fixups.h, since it's easy to understand that it's generated anyway when it's in the build directory.

Flat hierarchies are nice, IMO, and avoiding directories that only have another directory in them (like zephyr/include/, which only seems to have zephyr/include/generated/ in it).

[erwango]

The naming seems a bit redundant at the moment, like zephyr/include/generated/generated_dts_board_fixups.h. I wonder if it could just be zephyr/include/dts_board_fixups.h, since it's easy to understand that it's generated anyway when it's in the build directory.

What about zephyr/include/dts/board_fixups.h then ? ;-)

Flat hierarchies are nice, IMO, and avoiding directories that only have another directory in them (like zephyr/include/, which only seems to have zephyr/include/generated/ in it).

Agreed, not sure the include makes any sense here (besides we can find .c and .ld files in it).

[erwango]

Closing as the current solution is far from description on this PR