tests: Move the console stubs to a dedicated directory

Move the console functions definitions out from lib/b64_decode code to
a dedicated directory.

Signed-off-by: Anna Karas <aka@semihalf.com>
Change-Id: I22a6a592f0d4d509f19920f4ad2b18e8ed83a03e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43285
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

tests/stubs/console.c

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+
+int do_printk(int msg_level, const char *fmt, ...)
+{
+	return 0;
+}
+
+int do_vprintk(int msg_level, const char *fmt, va_list args)
+{
+	return 0;
+}