So... waking up once per second turns out to be a dumb idea because it
regresses the stop watch and HRS tools (which now also only wake up once
per second).
Undo this change but sprinkle a few more micropython.native decorations
on methods used on the wakeup path to minimise power.
Fixes: fb18705b9b ("manager/rtc: Experimental power saving technique")
Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>