Previously, there was a very tight allowed margin (100us), then some
special cases for platforms for which the test would otherwise fail,
increasing the margin.
This turned out to be a maintanance burden, as each slightly special
board needed a PR adding the special case.
This commit sets a quite large margin (1000us, 0.1% of total delay),
which should be large enough to not trip over platform-induced timer
inaccuracies, but still verify that the module is using timers
correctly.
(This is not a timer accuracy test.)
Kaspar Schleiser
a9cd9433f0