MSEC and SEC are now usable on TIMER(0) without having USEC
pm is configured by used hardware
OLD configuration values are translated for backward compatibility
prefer rtt for ZTIMER_SEC
avoid doing partial ztimer setup if auto_init_ztimer is disabled
before this patch some const pointers might have been definend to values
that a user who disables auto_init for ztimer does not like.
wire up ZTIMER_SEC to the existing RTC backend, or RTT backend, or periph_timer
backend (in this order of preference).
Update sys/ztimer/auto_init.c
Co-authored-by: Leandro Lanzieri <leandro.lanzieri@haw-hamburg.de>
ztimer_clock are meant to be chained. At the end of the chaine
there is always a timer device object (periph_rtt/rtc/timer).
Since ZTIMER_MSEC and ZTIMER_USEC can be the scaled/shifted with
respect to the base periph_rtt/rtc/timer it makes sense to chain
other ZTIMER_XXX on top of the base rtc/timer/rtt in order to avoid
chained convertions.
