pyb.delay and pyb.udelay now use systick if IRQs are enabled, otherwise
they use a busy loop. Thus they work correctly when IRQs are disabled.
The busy loop is computed from the current CPU frequency, so works no
matter the CPU frequency.
SysTick IRQ now increases millisecond counter directly (ie without
calling HAL_IncTick). Provide our own version of HAL_Delay that does a
wfi while waiting. This more than halves power consumption when running
a loop containing a pyb.delay call. It used to be like this, but new
version of HAL library regressed this feature.
I also removed trailing spaces from modpyb.c which affected a couple
of lines technically not part of this patch.
Tested using: https://github.com/dhylands/upy-examples/blob/master/micros_test.py
which eventually fails due to wraparound issues (I could fix the test to compensate
but didn't bother)
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
