QS8 Sigmoid operator

PiperOrigin-RevId: 395713278
diff --git a/include/xnnpack.h b/include/xnnpack.h
index 06cd2ff..1e8a891 100644
--- a/include/xnnpack.h
+++ b/include/xnnpack.h
@@ -2185,6 +2185,26 @@
   int8_t* output,
   pthreadpool_t threadpool);
 
+enum xnn_status xnn_create_sigmoid_nc_qs8(
+  size_t channels,
+  size_t input_stride,
+  size_t output_stride,
+  int8_t input_zero_point,
+  float input_scale,
+  int8_t output_zero_point,
+  float output_scale,
+  int8_t output_min,
+  int8_t output_max,
+  uint32_t flags,
+  xnn_operator_t* sigmoid_op_out);
+
+enum xnn_status xnn_setup_sigmoid_nc_qs8(
+  xnn_operator_t sigmoid_op,
+  size_t batch_size,
+  const int8_t* input,
+  int8_t* output,
+  pthreadpool_t threadpool);
+
 enum xnn_status xnn_create_subtract_nd_qs8(
   int8_t input1_zero_point,
   float input1_scale,