Rasmus Villemoes authored Sep 10, 2019 and Stefano Babic committed Jan 07, 2020

It's true that booting normally doesn't take long enough for the
register to roll (which actually happens in a little over an hour, not
just a few seconds). However, the counter starts at power-on, and if
the board is held in reset to be booted over USB, one actually risks
hitting wrap-around during boot, which can both result in too short
delays (if the "st += delay" calculation makes st small) and
theoretically also unbound delays (if st ends up being UINT_MAX and
one just misses sampling digctl_microseconds at that point).

It doesn't take more code to DTRT, and once bitten, twice shy.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>