Add a PKI target

Author: srasoamiaramanana-ledger

include/os_pki.h

@@ -99,6 +99,7 @@ enum {
     CERTIFICATE_TARGET_DEVICE_NANOSP,
     CERTIFICATE_TARGET_DEVICE_STAX,
     CERTIFICATE_TARGET_DEVICE_FLEX,
+    CERTIFICATE_TARGET_DEVICE_APEXP,
     CERTIFICATE_TARGET_DEVICE_UNKNOWN
 };