Bluetooth: Add support for Read Local Simple Pairing Options

With the Read Local Simple Pairing Options command it is possible to
retrieve the support for max encryption key size supported by the
controller and also if the controller correctly verifies the ECDH public
key during pairing.

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