Revert "Bluetooth: Always request for user confirmation for Just Works"

This reverts commit 92516cd9.

Thi commit "Bluetooth: Always request for user confirmation for Just
Works" prevents BLE devices pairing in (at least) the Raspberry Pi OS
GUI. After reverting it, pairing works again.

If another solution to the problem is found then this reversion will
be removed.

See: https://github.com/raspberrypi/linux/issues/4139



Signed-off-by: Phil Elwell <phil@raspberrypi.com>