drivers/arm/scmi: allow use of multiple SCMI channels

On systems that have multiple platform components that can interpret the
SCMI messages, there is a need to support multiple SCMI channels (one
each to those platform components). Extend the existing SCMI interface
that currently supports only a single SCMI channel to support multiple
SCMI channels.

Change-Id: Ice4062475b903aef3b5e5bc37df364c9778a62c5
Signed-off-by: Aditya Angadi <aditya.angadi@arm.com>
diff --git a/plat/arm/board/juno/juno_topology.c b/plat/arm/board/juno/juno_topology.c
index 052ab9f..075f512 100644
--- a/plat/arm/board/juno/juno_topology.c
+++ b/plat/arm/board/juno/juno_topology.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -20,7 +20,7 @@
 		.ring_doorbell = &mhu_ring_doorbell,
 };
 
-scmi_channel_plat_info_t *plat_css_get_scmi_info(void)
+scmi_channel_plat_info_t *plat_css_get_scmi_info(int channel_id)
 {
 	return &juno_scmi_plat_info;
 }