In order for interrupt-based wake-ups (as introduced by #1142) to work concurrently with time.Sleep, we need to make some per-board changes.

Previously, sleepTicks (the function used as an interface between the scheduler and the hardware timer) was defined to block until the timer completed, since there was nothing else to do. Now we need to change this so that it bails out when an interrup

Is your enhancement proposal related to a problem? Please describe.
Refer to zephyrproject-rtos/zephyr#27357 (comment)
and
zephyrproject-rtos/zephyr#27357 (comment)

Describe the solution you'd like

• Use sys_get_le24() to pass crc_init value
• Define CRC polynomial and use the define instead of magic numbers.

Resurrecting the second bullet from #1334

• Figure out how to fix favicon / logo more generally (here's a start https://github.com/tock/tock/tree/doc-updates)

If you got to f.e. https://circuitpython.readthedocs.io/en/latest/CONTRIBUTING.html
Clicking on any link that is supposed to go to a markdown file in the github repo yields a 404 because it removes the file extension.
F.e. instead of linking to https://github.com/adafruit/circuitpython/blob/main/CODE_OF_CONDUCT.md (notice the .md)
it links to `https://github.com/adafruit/circuitpython/blo

Implement some test cases for standard memset()