drm/i915: Unify engine init loop

With the unified common engine setup done, and the execlist engine
initialization loop clearly split into two phases, we can eliminate
the separate legacy engine initialization code.

v2: Fix cleanup path for legacy.
v3: Rename constructors. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index f8eeb50..a25eac1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -484,11 +484,11 @@
 int intel_init_pipe_control(struct intel_engine_cs *engine, int size);
 void intel_fini_pipe_control(struct intel_engine_cs *engine);
 
-int intel_init_render_ring_buffer(struct drm_device *dev);
-int intel_init_bsd_ring_buffer(struct drm_device *dev);
-int intel_init_bsd2_ring_buffer(struct drm_device *dev);
-int intel_init_blt_ring_buffer(struct drm_device *dev);
-int intel_init_vebox_ring_buffer(struct drm_device *dev);
+int intel_init_render_ring_buffer(struct intel_engine_cs *engine);
+int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine);
+int intel_init_bsd2_ring_buffer(struct intel_engine_cs *engine);
+int intel_init_blt_ring_buffer(struct intel_engine_cs *engine);
+int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine);
 
 u64 intel_ring_get_active_head(struct intel_engine_cs *engine);
 static inline u32 intel_engine_get_seqno(struct intel_engine_cs *engine)