bluetooth: controller: ll_sw: nordic: align to nrfx 3.7.0

Some enums have been renamed:

- NRF_CCM_EVENT_ENDCRYPT -> NRF_CCM_EVENT_END
- NRF_CCM_TASK_CRYPT -> NRF_CCM_TASK_START

Also adjust some TX power level settings (26/28dBm not always available
depending on the SoC revision).

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>