drm/i915/tracepoints: Add hw_id to context tracepoints

It is useful to provide this info to match the one provided
in the request tracepoints.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170221091350.14605-1-tvrtko.ursulin@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_trace.h

@@ -747,17 +747,19 @@ DECLARE_EVENT_CLASS(i915_context,
 	TP_STRUCT__entry(
 			__field(u32, dev)
 			__field(struct i915_gem_context *, ctx)
+			__field(u32, hw_id)
 			__field(struct i915_address_space *, vm)
 	),
 
 	TP_fast_assign(
+			__entry->dev = ctx->i915->drm.primary->index;
 			__entry->ctx = ctx;
+			__entry->hw_id = ctx->hw_id;
 			__entry->vm = ctx->ppgtt ? &ctx->ppgtt->base : NULL;
-			__entry->dev = ctx->i915->drm.primary->index;
 	),
 
-	TP_printk("dev=%u, ctx=%p, ctx_vm=%p",
-		  __entry->dev, __entry->ctx, __entry->vm)
+	TP_printk("dev=%u, ctx=%p, ctx_vm=%p, hw_id=%u",
+		  __entry->dev, __entry->ctx, __entry->vm, __entry->hw_id)
 )
 
 DEFINE_EVENT(i915_context, i915_context_create,