igt/drv_hangman: Inject a true hang
igt/drv_hangman: Inject a true hang

Wean drv_hangman off the atrocious stop_rings and use a real GPU hang
instead.

Signed-off-by: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>

tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools