Merge branch 'feature/ulp_stop' into 'master'

ULP: add functions for stopping/restarting the ulp-riscv

Closes IDFGH-6588

See merge request espressif/esp-idf!16853

examples/system/ulp_riscv/ds18b20_onewire/main/ulp/main.c

@@ -148,7 +148,7 @@ int main (void)
         break;
     }
 
-    /* ulp_riscv_shutdown() is called automatically when main exits,
+    /* ulp_riscv_halt() is called automatically when main exits,
        main will be executed again at the next timeout period,
        according to ulp_set_wakeup_period()
      */

examples/system/ulp_riscv/gpio/main/ulp/main.c

@@ -36,6 +36,6 @@ int main (void)
             break;
         }
     }
-    /* ulp_riscv_shutdown() is called automatically when main exits */
+    /* ulp_riscv_halt() is called automatically when main exits */
     return 0;
 }