1. Rename MACROs SYSTEM_WIFI_RST_EN register bit fields to be more recognizable
2. reset Bluetooth baseband and MAC bits to fix the issue of task watchdog triggered during controller initialization due to invalid hardware state
* add esp-phy-lib submodule
* move libphy.a and phy_init.c from esp_wifi to esp_phy
* move librtc.a from esp_wifi to esp_phy
* move libbtbb.a from bt to esp_phy
* corresponding updates to build system