tests/console: Add tests for log message routing behavior

Change-Id: Id978cfe4fa45fef9edbc3d3b55606ff6973521c5
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55356
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>

src/console/init.c

@@ -13,7 +13,8 @@
 static int console_inited;
 static int console_loglevel;
 
-static inline int get_log_level(void)
+int get_log_level(void);
+int get_log_level(void)
 {
 	if (console_inited == 0)
 		return -1;