drm/i915: Make intel_logical_ring_begin() static

The only usage of intel_logical_ring_begin() is within intel_lrc.c so it can be
made static. To avoid a forward declaration at the top of the file, it and bunch
of other functions have been shuffled upwards.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tomas Elf <tomas.elf@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_lrc.h

@@ -63,9 +63,6 @@ static inline void intel_logical_ring_emit(struct intel_ringbuffer *ringbuf,
 	iowrite32(data, ringbuf->virtual_start + ringbuf->tail);
 	ringbuf->tail += 4;
 }
-int intel_logical_ring_begin(struct intel_ringbuffer *ringbuf,
-			     struct intel_context *ctx,
-			     int num_dwords);
 
 /* Logical Ring Contexts */
 void intel_lr_context_free(struct intel_context *ctx);