include: Move snprintf to stdio.h

Move snprintf to stdio.h since it is needed by exteranl libraries.

Signed-off-by: Raymond Mao <raymond.mao@linaro.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

test/dm/scmi.c

@@ -18,7 +18,7 @@
 #include <scmi_agent.h>
 #include <scmi_agent-uclass.h>
 #include <scmi_protocols.h>
-#include <vsprintf.h>
+#include <stdio.h>
 #include <asm/scmi_test.h>
 #include <dm/device-internal.h>
 #include <dm/test.h>

test/print_ut.c

@@ -9,6 +9,7 @@
 #include <log.h>
 #include <mapmem.h>
 #include <version_string.h>
+#include <stdio.h>
 #include <vsprintf.h>
 #include <test/suites.h>
 #include <test/test.h>