tree: Use <stdio.h> for snprintf

<stdio.h> header is used for input/output operations (such as printf,
scanf, fopen, etc.). Although some input/output functions can manipulate
strings, they do not need to directly include <string.h> because they
are declared independently.

Change-Id: Ibe2a4ff6f68843a6d99cfdfe182cf2dd922802aa
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82665
Reviewed-by: Yidi Lin <yidilin@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/ec/google/chromeec/audio_codec/audio_codec.c

@@ -5,6 +5,8 @@
 #include <console/console.h>
 #include <device/device.h>
 #include <device/path.h>
+#include <stdio.h>
+
 #include "chip.h"
 
 #define CROS_EC_AUDIO_CODEC_HID		"GOOG0013"

src/ec/google/chromeec/ec_dptf_helpers.c

@@ -4,6 +4,7 @@
 #include <acpi/acpigen_dptf.h>
 #include <ec/google/common/dptf.h>
 #include <drivers/intel/dptf/chip.h>
+#include <stdio.h>
 
 #include "chip.h"
 /*

src/ec/google/chromeec/ec_smbios.c

@@ -2,6 +2,7 @@
 
 #include <ec/google/chromeec/ec.h>
 #include <console/console.h>
+#include <stdio.h>
 #include <string.h>
 #include <smbios.h>
 

src/ec/google/chromeec/i2c_tunnel/i2c_tunnel.c

@@ -5,6 +5,7 @@
 #include <console/console.h>
 #include <device/device.h>
 #include <device/path.h>
+#include <stdio.h>
 #include <string.h>
 #include "chip.h"
 

src/ec/google/chromeec/mux/conn/conn.c

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 
 #include <acpi/acpigen.h>
+#include <stdio.h>
 
 #include "chip.h"