* Unify the system peripheral
Whilst the PCR, SYSTEM and DPORT peripherals are different, we currently
use them all in the same way. This PR unifies the peripheral name in the
hal to `SYSTEM`. The idea is that they all do the same sort of thing, so
we can collect them under the same name, and later down the line we can
being to expose differences under an extended API.
The benifits to this are imo quite big, the examples now are all identical,
which makes things easier for esp-wifi, and paves a path towards the
multichip hal.
Why not do this in the PAC? Imo the pac should be as close to the
hardware as possible, and the HAL is where we should abstractions such
as this.
* changelog
* deep sleep api for esp32
* move to list of wakeup sources
* improve Ext0WakeupSource - still WIP
* add deep sleep with timer wakeup example
add Ext0 wakeup source (WIP/Non-working)
* removed alloc (using heapless now)
* Sleep: ext0 wakeup working
* add sleep_timer_ext0 example
* API change: move sleep into RTC as sleep, sleep_deep, sleep_light
* fix sleep examples for new API
* sleep only implemented for esp32 at this time
* sleep only implemented for esp32 at this time
* Implement a simple RTCPin trait to support sleep
* implement RTCPin for all xtensa SOC
* cargo fmt & update changelog
* fix change log order (accidentally swaped during rebase)
* implement Drop for Ext0WakeupSource
* added Ext1 wakeup source
* cargo fmt
* healpess was unused, removed
* fix pase macro usage
