bluetooth: nordic: Update nrfx HAL calls with pointers to HW instances

Update calls to nrfx HAL functions to reflect API changes introduced in
nrfx 2.0.0. All these functions are now called with the first parameter
pointing to the structure of registers of the relevant peripheral.

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>