Bluetooth: hci: Use extended VS fatal error in hci and hci_rpmsg sample

Provide common helper functions to create extended extended Zephyr
Fatal Error functionality in HCI common code.

Use the implementation in hci_rpmsg sample.

The sample didn't provide an information about Controllers assert
or system fatal error to an application code while run with nRF5340
SoC. The goal for hci_rpmsg sample change is to enhance user experience
for conformance testing of the Bluetooth Controller while executed with
nRF5340.

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>