driver(Ledc): fix the bug that ledc low-sleep channel can not work when chip in light-sleep mode
driver(Ledc): fix the bug that ledc low-sleep channel can not work when chip in light-sleep mode

    `esp_light_sleep_start` will disable the RTC8M_CLK, which will cause the LEDC low-speed channel to not work in light-sleep mode

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf