zkey: Support EP11 host library version 4

Try to load libep11.so.4 if available, but fallback to older
library versions if not.

Reviewed-by: Jörg Schmidbauer <jschmidb@de.ibm.com>
Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

zkey/ep11.c

@@ -35,7 +35,7 @@
  * Definitions for the EP11 library
  */
 #define EP11_LIBRARY_NAME	"libep11.so"
-#define EP11_LIBRARY_VERSION	3
+#define EP11_LIBRARY_VERSION	4
 #define EP11_WEB_PAGE		"http://www.ibm.com/security/cryptocards"
 
 /**