SPM: Add interrupt handling support for SFN backend

This patch adds the interrupt handling support for SFN backend:
- Add two new ops in backend
- Add IRQ APIs for SFN interface

Change-Id: If5c694800f6c882f5852c9092143f4db5f0f4bd1
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/secure_fw/spm/include/ffm/backend.h b/secure_fw/spm/include/ffm/backend.h
index d5e470c..d430da5 100644
--- a/secure_fw/spm/include/ffm/backend.h
+++ b/secure_fw/spm/include/ffm/backend.h
@@ -40,6 +40,18 @@
      * Return the connection handle or the acked status code.
      */
     psa_status_t (*replying)(struct conn_handle_t *handle, int32_t status);
+
+    /*
+     * Runtime model-specific Partition wait operation.
+     * Put the Partition to a status that waits for signals.
+     */
+    void (*wait)(struct partition_t *p_pt, psa_signal_t signals);
+
+    /*
+     * Runtime model-specific Partition wake up operation.
+     * Wakes up the Partition with the give signals.
+     */
+    void (*wake_up)(struct partition_t *p_pt, psa_signal_t signals);
 };
 
 /* RUNTIME MODEL BACKENDS DECLARATION */