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/env/flash.c b/env/flash.c
index e05f7ef..3198147 100644
--- a/env/flash.c
+++ b/env/flash.c
@@ -14,6 +14,7 @@
 #include <env.h>
 #include <env_internal.h>
 #include <flash.h>
+#include <log.h>
 #include <linux/stddef.h>
 #include <malloc.h>
 #include <search.h>