drm/i915/selftests: Add a safety net to live_workarounds

Since live_workarounds poke around the w/a registers and checks to see
if they survive across a reset, we are prone to fouling the machine and
leaving it in a non-recoverable state. Wrap the probe inside a timeout
to abort the test if the reset fails.

v2: Include GEM_TRACE on declaring wedged.
v3: Add a few includes to make the header look standalone.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107188


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180711122952.18448-1-chris@chris-wilson.co.uk