libc: Use printf and snprintf across codebase

tf_printf and tf_snprintf are now called printf and snprintf, so the
code needs to be updated.

Change-Id: Iffeee97afcd6328c4c2d30830d4923b964682d71
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/plat/hisilicon/hikey/hisi_ipc.c b/plat/hisilicon/hikey/hisi_ipc.c
index 4936f83..7e02f3a 100644
--- a/plat/hisilicon/hikey/hisi_ipc.c
+++ b/plat/hisilicon/hikey/hisi_ipc.c
@@ -11,6 +11,7 @@
 #include <mmio.h>
 #include <platform_def.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <string.h>
 
 static int ipc_init;
@@ -63,7 +64,7 @@
 static void hisi_ipc_send(unsigned int ipc_num)
 {
 	if (!ipc_init) {
-		tf_printf("error ipc base is null!!!\n");
+		printf("error ipc base is null!!!\n");
 		return;
 	}