* 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
* Functions for setting and clearing interrupts
as well as function to read interrupt mask
should be clearer now.
* Using hal layer interrupt set and clear
functions in esp_wifi component
