drm/i915: Update ring->emit_bb_start() to take a request structure

Updated the ring->emit_bb_start() implementation to take a request instead of a
ringbuf/context pair.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tomas Elf <tomas.elf@intel.com>
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 bf679ae..1f11c32 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -270,8 +270,7 @@
 	int		(*emit_flush)(struct drm_i915_gem_request *request,
 				      u32 invalidate_domains,
 				      u32 flush_domains);
-	int		(*emit_bb_start)(struct intel_ringbuffer *ringbuf,
-					 struct intel_context *ctx,
+	int		(*emit_bb_start)(struct drm_i915_gem_request *req,
 					 u64 offset, unsigned dispatch_flags);
 
 	/**