Bluetooth: Introduce BT_BREDR and BT_LE config options

The current kernel options do not make it clear which modules are for
Bluetooth Classic (BR/EDR) and which are for Bluetooth Low Energy (LE).

To make it really clear, introduce BT_BREDR and BT_LE options with
proper dependencies into the different modules. Both new options
default to y to not create a regression with previous kernel config
files.

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