modules: hal_nordic: nrf_802154: CCA threshold config in dBm

The nrf-802154 component of hal_nordic is updated.
The CCA threshold configuration is now done in dBm units, instead of
hardware-dependent scale.
Fixed a bug, where the CONFIG_NRF_802154_CCA_ED_THRESHOLD units were
different from the NRF_802154_CCA_ED_THRESHOLD units. Now all
configuration is done in dBm.

Signed-off-by: Rafał Kuźnia <rafal.kuznia@nordicsemi.no>