plat: xilinx: zynqmp: Add checksum support for IPI data

This patch adds support for CRC checksum for IPI data when the
macro ZYNQMP_IPI_CRC_CHECK is defined.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Change-Id: Ic981f162666b3c1fffeb1b9fef3ee7714ecd889d
diff --git a/plat/xilinx/common/include/pm_ipi.h b/plat/xilinx/common/include/pm_ipi.h
index 16db5c5..7bcf596 100644
--- a/plat/xilinx/common/include/pm_ipi.h
+++ b/plat/xilinx/common/include/pm_ipi.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -26,5 +26,8 @@
 void pm_ipi_irq_enable(const struct pm_proc *proc);
 void pm_ipi_irq_clear(const struct pm_proc *proc);
 uint32_t pm_ipi_irq_status(const struct pm_proc *proc);
+#if ZYNQMP_IPI_CRC_CHECK
+uint32_t calculate_crc(uint32_t payload[PAYLOAD_ARG_CNT], uint32_t buffersize);
+#endif
 
 #endif /* PM_IPI_H */