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/powerpc/lib/spl.c b/arch/powerpc/lib/spl.c
index d90a6e2..d4a6057 100644
--- a/arch/powerpc/lib/spl.c
+++ b/arch/powerpc/lib/spl.c
@@ -4,6 +4,7 @@
  */
 #include <common.h>
 #include <config.h>
+#include <log.h>
 #include <spl.h>
 #include <image.h>
 #include <linux/compiler.h>