esp32: Remove deprecated system_deep_sleep function

Deprecated since ESP-IDF V3.0

components/esp32/include/esp_sleep.h

@@ -295,16 +295,6 @@ esp_err_t esp_light_sleep_start(void);
  */
 void esp_deep_sleep(uint64_t time_in_us) __attribute__((noreturn));
 
-/**
- * @brief Enter deep-sleep mode
- *
- * Function has been renamed to esp_deep_sleep.
- * This name is deprecated and will be removed in a future version.
- *
- * @param time_in_us  deep-sleep time, unit: microsecond
- */
-void system_deep_sleep(uint64_t time_in_us) __attribute__((noreturn, deprecated));
-
 
 /**
  * @brief Get the wakeup source which caused wakeup from sleep

components/esp32/sleep_modes.c

@@ -360,8 +360,6 @@ esp_err_t esp_light_sleep_start(void)
     return err;
 }
 
-void system_deep_sleep(uint64_t) __attribute__((alias("esp_deep_sleep")));
-
 esp_err_t esp_sleep_disable_wakeup_source(esp_sleep_source_t source)
 {
     // For most of sources it is enough to set trigger mask in local