Bluetooth: Check for force_lesc_support when enabling SMP over BR/EDR

The SMP over BR/EDR support for cross-transport pairing should also be
enabled when the debugfs setting force_lesc_support has been enabled.

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