Add a feature for the ESP32-C2 to`esp-hal-common` and update some `cfg`s
Organize the `esp-hal-common` imports and exports and update to include the ESP32-C2
* Update the build script to inject a configuration value for the enabled chip
* Update all cfg gates to use the new symbols instead of the chip features
* Inject architecture and core count symbols as well, update as needed
* Organize the imports and exports of `esp-hal-common`
* initial systimer impl
* Add systimer example
* Make Alarms real singletons
* Remove runtime Option, turn into compile error
* Make Systimer::now() not take self
* refactor shared alarm methods
* Implement esp32c3 delay with monotonic SystemTimer::now()
* Add extend systimer support to esp32s3 and add example
* systimer: esp32s2 support
