Bluetooth: Introduce HCI_QUIRK_SIMULTANEOUS_DISCOVERY

Some controllers allow both LE scan and BR/EDR inquiry to run at
the same time, while others allow only one, LE SCAN or BR/EDR
inquiry at given time.

Since this is specific to each controller, add a new quirk setting
that allows drivers to tell the core wether given controller can
do both LE scan and BR/EDR inquiry at same time.

Signed-off-by: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>