This changes lots of files to unify `board.h` across ports. It adds
`board_deinit` when CIRCUITPY_ALARM is set. `main.c` uses it to
deinit the board before deep sleeping (even when pretending.)
Deep sleep is now a two step process for the port. First, the
port should prepare to deep sleep based on the given alarms. It
should set alarms for both deep and pretend sleep. In particular,
the pretend versions should be set immediately so that we don't
miss an alarm as we shutdown. These alarms should also wake from
`port_idle_until_interrupt` which is used when pretending to deep
sleep.
Second, when real deep sleeping, `alarm_enter_deep_sleep` is called.
The port should set any alarms it didn't during prepare based on
data it saved internally during prepare.
ESP32-S2 sleep is a bit reorganized to locate more logic with
TimeAlarm. This will help it scale to more alarm types.
Fixes#3786
Add aliases for SDI, SDO and EN, so that pin names match the text on the
PCB to avoid confusion.
Also disable all pins from port B, because that package of SAMD21
doesn't have port B.
