[PATCH v3] selftests: complete kselftest include centralization

[Bala-Vignesh-Reddy]

Hey Brendan,

Thanks for the report.

This issue is caused by my change that centralized the kselftest.h
include path in lib.mk, while the x86 selftests Makefile overwrites CFLAGS
with :=, so shared include path unable to find kselftest.h. The fix is to
explicity add the selftests include directory to CFLAGS in
tools/testing/selftests/x86/Makefile.

I have already submitted this:
[PATCH] selftests/x86: Add selftests include path for kselftest.h after centralization
Link: https://lore.kernel.org/lkml/20251022062948.162852-1-reddybalavignesh9979@gmail.com/

it has been tested and confirmed working.
 Tested-by: Anders Roxell <anders.roxell at linaro.org>

Once that patch is merged, the x86 selftests build issue should be
resolved.

Thanks
Bala Vignesh