kms_frontbuffer_tracking: add fliptrack subtest
kms_frontbuffer_tracking: add fliptrack subtest

The current upstream Kernel code stops and then restarts FBC at every
page flip. I am working on patches to keep FBC enabled all the time,
so this brings the possibility of having the hardware tracking
mechanism looking at the old buffer instead of the new one. This test
should catch this problem.

Signed-off-by: Paulo Zanoni <cc0e04a2103c45cd195651d976f79813d0f66bdf@intel.com>

chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools