drivers: bluetooth: nble: restructures Bluetooth Kconfig options

This moves both the Bluetooth HCI and NBLE drivers under
"Bluetooth Drivers" category. This also adds a selection for
choosing Bluetooth stacks as the bulk of both HCI and NBLE stacks
cannot be compiled together.

Note that this does not move the source files. That should be
done in a separate change.

Change-Id: I32fa7097ada0fdc52bcc745adb78c7273f4023c6
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
11 files changed