drm-ci: flaky tests for vkms driver testing

[Vignesh Raman]

Hi Maintainers,

There are some flaky tests reported for vkms driver testing in drm-ci.

# Board Name: vkms
# Failure Rate: 50
# IGT Version: 1.28-g0df7b9b97
# Linux Version: 6.9.0-rc7
kms_cursor_legacy at long-nonblocking-modeset-vs-cursor-atomic
kms_flip at basic-flip-vs-wf_vblank
kms_flip at flip-vs-expired-vblank-interruptible
kms_flip at flip-vs-wf_vblank-interruptible
kms_flip at plain-flip-fb-recreate-interruptible
kms_flip at plain-flip-ts-check
kms_flip at plain-flip-ts-check-interruptible
kms_flip at flip-vs-absolute-wf_vblank
kms_flip at flip-vs-absolute-wf_vblank-interruptible
kms_flip at flip-vs-blocking-wf-vblank

Will add these tests in drivers/gpu/drm/ci/xfails/vkms-none-flakes.txt 
(https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/Documentation/gpu/automated_testing.rst#n70)

Please could you have a look at these test results and let us know if 
you need more information. Thank you.

Regards,
Vignesh