modules: hal_nordic: use CLOCK_CONTROL_NRF2 for HFCLK request/release

Makes 802.15.4 use the API under CONFIG_CLOCK_CONTROL_NRF2
in nrf_clock_control.h to request/release HFCLK.

Previous HFCLK requesting/releasing on nRF54H20 was more
of a workaround and could produce issues when
comes to sharing the resources.

Signed-off-by: Piotr Koziar <piotr.koziar@nordicsemi.no>