drivers: timer: nrf: Adapt to clock_control changes

Adapted driver to clock_control changes (usage of onoff manager).
Since timer is permanenty requesting the clock, it is using API
dedicated for that: z_nrf_clock_control_lf_on().

Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
1 file changed