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/cmd/source.c b/cmd/source.c
index cd58924..b6c709a 100644
--- a/cmd/source.c
+++ b/cmd/source.c
@@ -18,6 +18,7 @@
 #include <command.h>
 #include <env.h>
 #include <image.h>
+#include <log.h>
 #include <malloc.h>
 #include <mapmem.h>
 #include <asm/byteorder.h>