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/board/freescale/mpc8536ds/mpc8536ds.c b/board/freescale/mpc8536ds/mpc8536ds.c
index bfbb8a5..582c5b4 100644
--- a/board/freescale/mpc8536ds/mpc8536ds.c
+++ b/board/freescale/mpc8536ds/mpc8536ds.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <command.h>
 #include <init.h>
+#include <log.h>
 #include <net.h>
 #include <pci.h>
 #include <asm/processor.h>