fix(scmi): mention "SCMI" in driver initialisation message

Currently the SCMI driver reports:
INFO:    Initializing driver on Channel 0
on the console, which is not very specific (which driver?).

Add "SCMI" to the message so the user knows what the firmware is trying
to initialise.

Change-Id: Id8202655d07b8e12fe07670d462c6202e6eae2f0
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/drivers/arm/css/scp/css_pm_scmi.c b/drivers/arm/css/scp/css_pm_scmi.c
index aeb7eda..5de2604 100644
--- a/drivers/arm/css/scp/css_pm_scmi.c
+++ b/drivers/arm/css/scp/css_pm_scmi.c
@@ -357,7 +357,7 @@
 	unsigned int composite_id, idx;
 
 	for (idx = 0; idx < PLAT_ARM_SCMI_CHANNEL_COUNT; idx++) {
-		INFO("Initializing driver on Channel %d\n", idx);
+		INFO("Initializing SCMI driver on channel %d\n", idx);
 
 		scmi_channels[idx].info = plat_css_get_scmi_info(idx);
 		scmi_channels[idx].lock = ARM_SCMI_LOCK_GET_INSTANCE;