fix(wdt): changed ESP32-C3 WDT to use XTAL as clock

This clock is unchanged even when CPU/APB frequency changes (e.g. due to esp_pm),
which means timeout period is correct even after such a change.

components/soc/esp32c6/include/soc/Kconfig.soc_caps.in

@@ -1007,6 +1007,10 @@ config SOC_TIMER_SUPPORT_ETM
     bool
     default y
 
+config SOC_MWDT_SUPPORT_XTAL
+    bool
+    default y
+
 config SOC_TWAI_CONTROLLER_NUM
     int
     default 2

components/soc/esp32c6/include/soc/soc_caps.h

@@ -418,6 +418,9 @@
 #define SOC_TIMER_GROUP_TOTAL_TIMERS      (2)
 #define SOC_TIMER_SUPPORT_ETM             (1)
 
+/*--------------------------- WATCHDOG CAPS ---------------------------------------*/
+#define SOC_MWDT_SUPPORT_XTAL              (1)
+
 /*-------------------------- TWAI CAPS ---------------------------------------*/
 #define SOC_TWAI_CONTROLLER_NUM         2
 #define SOC_TWAI_CLK_SUPPORT_XTAL       1