- esp_phy_enable() blocks in the unit test due to the FE related functions in modem clock registers are not enabled. This MR adds dependency of FE for PHY module.
* 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