imc-os: Derive device ID from private key bound to smartcard or TPM

conf/plugins/imc-os.opt

@@ -6,6 +6,10 @@ libimcv.plugins.imc-os.device_id =
 	Manually set the client device ID in hexadecimal format
    (e.g. 1083f03988c9762703b1c1080c2e46f72b99cc31)
 
+libimcv.plugins.imc-os.device_handle =
+	Manually set handle to a private key bound to a smartcard or TPM
+    (e.g. 0x81010004)
+
 libimcv.plugins.imc-os.device_pubkey =
 	Manually set the path to the client device public key
     (e.g. /etc/pts/aikPub.der)