usb_serial_jtag: Improve the code for the issue of usb cdc device unable to work during sleep

1. Remove RTC_CLOCK_BBPLL_POWER_ON_WITH_USB Kconfig option
   During sleep, BBPLL clock always gets disabled
   esp_restart does not disable BBPLL clock, so that first stage bootloader log can be printed
2. Add a new Kconfig option PM_NO_AUTO_LS_ON_USJ_CONNECTED
   When this option is selected, IDF will constantly monitor USB CDC port connection status.
   As long as it gets connected to a HOST, automatic light-sleep will not happen.

Closes https://github.com/espressif/esp-idf/issues/8507

components/soc/esp32s2/include/soc/rtc.h

@@ -423,6 +423,9 @@ void rtc_clk_cpu_freq_get_config(rtc_cpu_freq_config_t* out_config);
  * Short form for filling in rtc_cpu_freq_config_t structure and calling
  * rtc_clk_cpu_freq_set_config when a switch to XTAL is needed.
  * Assumes that XTAL frequency has been determined — don't call in startup code.
+ *
+ * @note Unlike on other chips, on ESP32S2, this function does not disable BBPLL after switching the CPU clock source
+ * to XTAL. If BBPLL wants to be turned off for power saving purpose, please use rtc_clk_cpu_freq_set_config.
  */
 void rtc_clk_cpu_freq_set_xtal(void);