* All components which won't build (yet) on Linux are excluded.
This enables switching to Linux in an application without
explicitly setting COMPONENTS to main in the main
CMakeLists.txt.
* ESP Timer provides headers for Linux now
* automatically disabling LWIP in Kconfig if it is not available
doc(linux): brought section
"Component Linux/Mock Support Overview" up to date
After refactoring the target components (e.g. esp32) no longer contained any real functionality.
What remained in these components have been moved elsewhere and the component itself deleted from the
build system.
- Introduce system time function and concept of system time provider.
esp_timer is system time provider when present.
- Set the reference point for system time, g_startup_time.
- Use the system time functions in newlib instead of calling esp_timer
functions directly
