drm/i915: Make intel_logical_ring_advance_and_submit() static

This function is only used in intel_lrc.c, so restrict it to that file. The
function was moved around to avoid a forward declaration and group it with its
user.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 8872a80..b7f3887 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -785,7 +785,7 @@
 	return 0;
 }
 
-/**
+/*
  * intel_logical_ring_advance_and_submit() - advance the tail and submit the workload
  * @ringbuf: Logical Ringbuffer to advance.
  *
@@ -794,9 +794,10 @@
  * on a queue waiting for the ELSP to be ready to accept a new context submission. At that
  * point, the tail *inside* the context is updated and the ELSP written to.
  */
-void intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf,
-					   struct intel_context *ctx,
-					   struct drm_i915_gem_request *request)
+static void
+intel_logical_ring_advance_and_submit(struct intel_ringbuffer *ringbuf,
+				      struct intel_context *ctx,
+				      struct drm_i915_gem_request *request)
 {
 	struct intel_engine_cs *ring = ringbuf->ring;