feat(realm): add host call to flush realm prints

add new host call to push out realm print buffer
buffer is flushed after every print statement

Change-Id: I6efa92a7c75ab7df4615a432802426de39d0032c
Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
diff --git a/realm/realm_debug.c b/realm/realm_debug.c
index d7989ca..1c4ee03 100644
--- a/realm/realm_debug.c
+++ b/realm/realm_debug.c
@@ -11,6 +11,7 @@
 
 #include <arch_helpers.h>
 #include <host_shared_data.h>
+#include <realm_rsi.h>
 
 /*
  * A printf formatted function used in the Realm world to log messages
@@ -31,6 +32,7 @@
 			strnlen((const char *)log_buffer, MAX_BUF_SIZE),
 			MAX_BUF_SIZE, fmt, args);
 	va_end(args);
+	rsi_exit_to_host(HOST_CALL_EXIT_PRINT_CMD);
 }
 
 void __attribute__((__noreturn__)) do_panic(const char *file, int line)