GIC: Add API to set interrupt routing

SPIs can be routed to either a specific PE, or to any one of all
available PEs.

API documentation updated.

Change-Id: I28675f634568aaf4ea1aa8aa7ebf25b419a963ed
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/bl31/interrupt_mgmt.h b/include/bl31/interrupt_mgmt.h
index 9a6a7fa..4f5a601 100644
--- a/include/bl31/interrupt_mgmt.h
+++ b/include/bl31/interrupt_mgmt.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,6 +17,11 @@
 #define INTR_TYPE_NS			U(2)
 #define MAX_INTR_TYPES			U(3)
 #define INTR_TYPE_INVAL			MAX_INTR_TYPES
+
+/* Interrupt routing modes */
+#define INTR_ROUTING_MODE_PE		0
+#define INTR_ROUTING_MODE_ANY		1
+
 /*
  * Constant passed to the interrupt handler in the 'id' field when the
  * framework does not read the gic registers to determine the interrupt id.