tools headers compiler: Pick the const_true() define from the kernel sources

tools headers compiler: Pick the const_true() define from the kernel sources

The sync of include/linux/bits.h with the kernel sources will make use
of this define, so add it to the tools/include/linux/compiler. variant
used to build tools/ living code.

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Yury Norov [NVIDIA] <yury.norov@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250519214126.1652491-7-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>