Bluetooth: move hci_get_random_address() to hci_sync

This function has no dependencies on the deprecated hci_request
mechanism, so has been moved unchanged to hci_sync.c

Signed-off-by: Brian Gix <brian.gix@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>