drm/shmem-helper: Make drm_gem_shmem_print_info() symbol GPL

Make drm_gem_shmem_print_info() exported symbol GPL to make it consistent
with the rest of drm-shmem exports. It's the only remaining drm-shmem
symbol that isn't GPL.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

drivers/gpu/drm/drm_gem_shmem_helper.c

@@ -782,7 +782,7 @@ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
 	drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);
 	drm_printf_indent(p, indent, "madv=%d\n", shmem->madv);
 }
-EXPORT_SYMBOL(drm_gem_shmem_print_info);
+EXPORT_SYMBOL_GPL(drm_gem_shmem_print_info);
 
 /**
  * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned