disable PHY and RF when stop WiFi and disable BT

1. Add disable PHY and RF when WiFi and BT are both disabled(including call sniffer disable API).

2. Do not init PHY and RF when cpu start. Init PHY and RF when call Wifi or BT start APIs(including sniffer enable API).

3. Add a temporary lib: librtc_clk.a and will delete it when CPU frequency switching function is done.

4. Add an function to get OS tick rate.

5. Do not put the whole pp.a in iram0, only put lmac.o, ieee80211_misc.o, ets_time.o and wdev.o in iram0.

components/esp32/rtc.h

@@ -135,6 +135,10 @@ void rtc_slp_prep_lite(uint32_t deep_slp, uint32_t cpu_lp_mode);
  */
 uint32_t rtc_sleep(uint32_t cycles_h, uint32_t cycles_l, uint32_t wakeup_opt, uint32_t reject_opt);
 
+/**
+ * @brief Shutdown PHY and RF. This is a temporary function.
+ */
+void pm_close_rf(void);
 
 #ifdef __cplusplus
 }