[watchdog] Fix WatchdogManager on single core apps (#16074)

esphome/components/watchdog/watchdog.cpp

@@ -6,7 +6,6 @@
 #include <cinttypes>
 #include <cstdint>
 #ifdef USE_ESP32
-#include <soc/soc_caps.h>
 #include "esp_idf_version.h"
 #include "esp_task_wdt.h"
 #endif
@@ -40,7 +39,7 @@ void WatchdogManager::set_timeout_(uint32_t timeout_ms) {
 #ifdef USE_ESP32
   esp_task_wdt_config_t wdt_config = {
       .timeout_ms = timeout_ms,
-      .idle_core_mask = (1 << SOC_CPU_CORES_NUM) - 1,
+      .idle_core_mask = (1U << CONFIG_FREERTOS_NUMBER_OF_CORES) - 1U,
       .trigger_panic = true,
   };
   esp_task_wdt_reconfigure(&wdt_config);