v6.6.78 regression: rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads

Hi there, I cannot build the `rtla` tool in the stable branch, version v6.6.80. The root cause appears to be commit 41955b6c268154f81e34f9b61cf8156eec0730c0 which first appeared in v6.6.78. Here's how the build failure looks like through Buildroot:

src/timerlat_hist.c: In function ‘timerlat_hist_apply_config’: src/timerlat_hist.c:908:60: error: ‘struct timerlat_hist_params’ has no member named ‘kernel_workload’ 908 | retval = osnoise_set_workload(tool->context, params->kernel_workload); | ^~ make[3]: *** [<builtin>: src/timerlat_hist.o] Error 1

A quick grep shows that that symbol is referenced, but not defined anywhere:

~/work/prog/linux-kernel[cesnet/2025-02-28] $ git grep kernel_workload tools/tracing/rtla/src/timerlat_hist.c: retval = osnoise_set_workload(tool->context, params->kernel_workload); tools/tracing/rtla/src/timerlat_top.c: retval = osnoise_set_workload(top->context, params->kernel_workload);

Maybe some prerequisite patch is missing?

With kind regards, Jan