drm/i915: Refactor scratch object allocation for gen2 w/a buffer

The gen2 w/a buffer is stuffed into the same slot as the gen5+ scratch
buffer. If we pass in the size we want to allocate for the scratch
buffer, both callers can use the same routine.

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/1467390209-3576-11-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index c8411f8..f1a0113 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2056,7 +2056,7 @@
 	engine->emit_flush = gen8_emit_flush_render;
 	engine->emit_request = gen8_emit_request_render;
 
-	ret = intel_init_pipe_control(engine);
+	ret = intel_init_pipe_control(engine, 4096);
 	if (ret)
 		return ret;