ulp-fsm: Update ulp-fsm ADC example with S3 support

Closes https://github.com/espressif/esp-idf/issues/7963

examples/system/ulp_fsm/ulp_adc/main/ulp/adc.S

@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
 /* ULP Example: using ADC in deep sleep
 
    This example code is in the Public Domain (or CC0 licensed, at your option.)
@@ -22,9 +27,9 @@
  */
 #include "soc/rtc_cntl_reg.h"
 #include "soc/soc_ulp.h"
+#include "example_config.h"
 
-	/* ADC1 channel 6, GPIO34 */
-	.set adc_channel, 6
+	.set adc_channel, EXAMPLE_ADC_CHANNEL
 
 	/* Configure the number of ADC samples to average on each measurement.
 	   For convenience, make it a power of 2. */