Epd2in9bc::new hangs the program

[JohnTheCoolingFan]

This issue comes from my research on #220 and I think giving it a fresh issue with proper formatting and less research/debug clutter is best, so I will close that one and open this one.

Tested on esp32 AND stm32, the Epd2in9bc::new initializer deadlocks the program.

Source code of the programs used to test this:

• esp32 nodemcu v1.1: https://github.com/JohnTheCoolingFan/esp32-epaper-calendar
• stm32 blue pill: https://github.com/JohnTheCoolingFan/stm32f1-epaper-test

According to the log messages, the program gets stuck when calling Epd2in9bc::new. Changing it to use Epd2in9 lets the program continue. Clearly something in that function is causing a deadlock.
It doesn't matter whether embassy is used or not.