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/esp32s3/include/soc/rtc.h

@@ -424,6 +424,10 @@ 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 This function always disables BBPLL after switching the CPU clock source to XTAL for power saving purpose.
+ * If this is unwanted, please use rtc_clk_cpu_freq_set_config. It helps to check whether USB Serial JTAG is in use,
+ * if so, then BBPLL will not be turned off.
  */
 void rtc_clk_cpu_freq_set_xtal(void);