use new pkcs11-helper interface to add providers

use new pkcs11-helper interface to add providers

The new interface in  pkcs11-helper 1.28 allows decoupling of provider
registration and initialization.
This allows modifying more (and future) properties apart from the
6 fixed ones supported as arguments to pkcs11h_addProvider().

With the new interface it is easier to see (from a code perspective)
which option is set to which value.
It's also not necessary to supply values for built-in defaults:
- slot_event_method=PKCS11H_SLOTEVENT_METHOD_AUTO
- slot_poll_interval=0

Signed-off-by: Marc Becker <marc.becker@astos.de>
Acked-by: Selva Nair <selva.nair@gmail.com>
Message-Id: <20221211191403.805-1-marc.becker@astos.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25643.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 45d9b0210a22353e587c29c5d3c3990346a4a189)