drm/i915: Move the magical deferred context allocation into the request

We can hide more details of execlists from higher level code by removing
the explicit call to create an execlist context from execbuffer and
into its first use by execlists.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-20-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_lrc.h

@@ -101,8 +101,6 @@ static inline void intel_logical_ring_emit_reg(struct intel_ringbuffer *ringbuf,
 
 void intel_lr_context_free(struct intel_context *ctx);
 uint32_t intel_lr_context_size(struct intel_engine_cs *engine);
-int intel_lr_context_deferred_alloc(struct intel_context *ctx,
-				    struct intel_engine_cs *engine);
 void intel_lr_context_unpin(struct intel_context *ctx,
 			    struct intel_engine_cs *engine);