Bluetooth: Provide option for changing LE advertising channel map

For testing purposes it is useful to provide an option to change the
advertising channel map. So add a debugfs option to allow this.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

diff --cc include/net/bluetooth/hci_core.h
Simple merge

diff --cc net/bluetooth/hci_core.c
Simple merge

diff --cc net/bluetooth/mgmt.c
Simple merge