Bluetooth: Add class of device control to the management interface

This patch adds the possibility for user space to fully control the
Class of Device value of local adapters. To control the service class
bits each UUID that's added comes with a service class "hint" which acts
as a mask of bits that the UUID needs to have enabled. The
set_service_cache management command is used to make sure we queue up
all UUID changes as user space initializes its drivers and then send a
single HCI_Write_Class_of_Device command when initialization is
complete.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>