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/spear/x600/fpga.c b/board/spear/x600/fpga.c
index d124d96..6dc3fb3 100644
--- a/board/spear/x600/fpga.c
+++ b/board/spear/x600/fpga.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <log.h>
 #include <spartan3.h>
 #include <command.h>
 #include <asm/gpio.h>