drm/i915: Pack params to engine->schedule() into a struct

Today we only want to pass along the priority to engine->schedule(), but
in the future we want to have much more control over the various aspects
of the GPU during a context's execution, for example controlling the
frequency allowed. As we need an ever growing number of parameters for
scheduling, move those into a struct for convenience.

v2: Move the anonymous struct into its own function for legibility and
ye olde gcc.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180418184052.7129-3-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -75,6 +75,7 @@
 #include "i915_gem_timeline.h"
 #include "i915_gpu_error.h"
 #include "i915_request.h"
+#include "i915_scheduler.h"
 #include "i915_vma.h"
 
 #include "intel_gvt.h"
@@ -3158,7 +3159,7 @@ int i915_gem_object_wait(struct drm_i915_gem_object *obj,
 			 struct intel_rps_client *rps);
 int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
 				  unsigned int flags,
-				  int priority);
+				  const struct i915_sched_attr *attr);
 #define I915_PRIORITY_DISPLAY I915_PRIORITY_MAX
 
 int __must_check