drm/i915: Update ring->flush() to take a requests structure

Updated the various ring->flush() functions to take a request instead of a ring.
Also updated the tracer to include the request id.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tomas Elf <tomas.elf@intel.com>
[danvet: Rebase since I didn't merge the addition of req->uniq.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 3f70687..4c0d329 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -180,7 +180,7 @@
 
 	void		(*write_tail)(struct intel_engine_cs *ring,
 				      u32 value);
-	int __must_check (*flush)(struct intel_engine_cs *ring,
+	int __must_check (*flush)(struct drm_i915_gem_request *req,
 				  u32	invalidate_domains,
 				  u32	flush_domains);
 	int		(*add_request)(struct intel_engine_cs *ring);