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/arch/mips/lib/stack.c b/arch/mips/lib/stack.c
index 4d1d98c..8f523fd 100644
--- a/arch/mips/lib/stack.c
+++ b/arch/mips/lib/stack.c
@@ -2,6 +2,7 @@
 
 #include <common.h>
 #include <init.h>
+#include <log.h>
 
 DECLARE_GLOBAL_DATA_PTR;