ESP32-C6: make basic light sleep work

[bjoernQ]

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Submission Checklist 📝

• I have updated existing examples or added new ones (if applicable).
• I have used cargo xtask fmt-packages command to ensure that all changed code is formatted correctly.
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Pull Request Details 📖

Description

sleep_light wasn't working for ESP32-C6. This fixes it.

Testing

Change the sleep_timer.rs example to this

//! Demonstrates light sleep with timer wakeup

//% CHIPS: esp32 esp32c3 esp32c6 esp32s3

#![no_std]
#![no_main]

use core::time::Duration;

use esp_backtrace as _;
use esp_hal::{
    clock::ClockControl,
    delay::Delay,
    entry,
    peripherals::Peripherals,
    rtc_cntl::{get_reset_reason, get_wakeup_cause, sleep::TimerWakeupSource, Rtc, SocResetReason},
    system::SystemControl,
    Cpu,
};
use esp_println::println;

#[entry]
fn main() -> ! {
    esp_println::logger::init_logger_from_env();
    
    let peripherals = Peripherals::take();
    let system = SystemControl::new(peripherals.SYSTEM);
    let clocks = ClockControl::boot_defaults(system.clock_control).freeze();

    let mut delay = Delay::new(&clocks);
    let mut rtc = Rtc::new(peripherals.LPWR, None);

    println!("up and runnning!");
    let reason = get_reset_reason(Cpu::ProCpu).unwrap_or(SocResetReason::ChipPowerOn);
    println!("reset reason: {:?}", reason);
    let wake_reason = get_wakeup_cause();
    println!("wake reason: {:?}", wake_reason);

    loop  {
        let timer = TimerWakeupSource::new(Duration::from_secs(4));
        println!("sleeping!");
        delay.delay_millis(300);
        rtc.sleep_light(&[&timer], &mut delay);

        println!("here");
        delay.delay_millis(2000);
    }
}

Power consumption will look like this

[bjoernQ]

in theory the ref-counting pattern is nice but if we do it we should do it for all clocks and for all chips (and it wasn't working correctly, didn't honor the initial state)

[bjoernQ]

in ESP-IDF the order of operations is like this - doesn't seem to make a difference but maybe better to align it

[jessebraham]

LGTM, thanks!

[SergioGasquez]

LGTM!