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/common/spl/spl_legacy.c b/common/spl/spl_legacy.c
index db5017a..82d0326 100644
--- a/common/spl/spl_legacy.c
+++ b/common/spl/spl_legacy.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <image.h>
+#include <log.h>
 #include <malloc.h>
 #include <spl.h>