feat(etm): add ETM LL and GPIO ETM support on esp32s31

Enable ETM caps and add S31 ETM/GPIO LL and retention support for
GPTimer ETM builds.

components/esp_hw_support/etm/include/esp_etm.h

@@ -8,6 +8,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include "esp_err.h"
+#include "hal/etm_types.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -32,6 +33,7 @@ typedef struct esp_etm_task_t *esp_etm_task_handle_t;
  * @brief ETM channel configuration
  */
 typedef struct {
+    etm_clock_source_t clk_src; /*!< Clock source for the ETM channel */
     /// Extra configuration flags for ETM channel
     struct etm_chan_flags {
         uint32_t allow_pd : 1; /*!< If set, driver allows the power domain to be powered off when system enters sleep mode.