refactor: logs to print SP/VM tags

Log functions were changing such that a log from
a VM will start with VM, and a log from an SP will
start with SP.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I7f616d521a27a938589b06dd1c266f42967e5868
diff --git a/src/dlog.c b/src/dlog.c
index 784c1f6..4901c3d 100644
--- a/src/dlog.c
+++ b/src/dlog.c
@@ -225,7 +225,11 @@
 {
 	lock();
 
-	print_raw_string("VM ");
+	if (ffa_is_vm_id(id)) {
+		print_raw_string("VM ");
+	} else {
+		print_raw_string("SP ");
+	}
 	print_num(id, 16, 0, 0);
 	print_raw_string(": ");