Move as much from sys_main.c to sfu_task_main.c as we can

[liquiddandruff]

Each platform has their own sys_main.c, duplicated with the same code.

We should see if we can move this initialization immediately inside vMainTask, before any other task is created (so before vMainTask can be pre-empted). I believe this has been attempted before, but due to reasons (e.g., desires to print to serial on bootup/MPU permission errors preventing certain hardware initialization to work when in a FreeRTOS task), necessitated adding these initialization to the sys_main.c.

Let's revisit this and see what can be improved.

[richarthurs]

@liquiddandruff I think we can close this now, eh?

[liquiddandruff]

That's right, thanks