Bluetooth: advmon offload MSFT add monitor

Enables advertising monitor offloading to the controller, if MSFT
extension is supported. The kernel won't adjust the monitor parameters
to match what the controller supports - that is the user space's
responsibility.

This patch only manages the addition of monitors. Monitor removal is
going to be handled by another patch.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Manish Mandlik <mmandlik@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Reviewed-by: Yun-Hao Chung <howardchung@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>