common: Drop log.h from common header

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/log/log_test.c b/test/log/log_test.c
index d29b559..4245372 100644
--- a/test/log/log_test.c
+++ b/test/log/log_test.c
@@ -8,6 +8,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <log.h>
 
 /* emit some sample log records in different ways, for testing */
 static int log_run(enum uclass_id cat, const char *file)