Bluetooth: Allow Microsoft extension to indicate curve validation

Some controllers don't support the Simple Pairing Options feature that
can indicate the support for P-192 and P-256 public key validation.
However they might support the Microsoft vendor extension that can
indicate the validiation capability as well.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>