common: Drop linux/bitops.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/gdsys/common/cmd_ioloop.c b/board/gdsys/common/cmd_ioloop.c
index 3b4494c..3ea2bec 100644
--- a/board/gdsys/common/cmd_ioloop.c
+++ b/board/gdsys/common/cmd_ioloop.c
@@ -7,6 +7,7 @@
 #include <common.h>
 #include <command.h>
 #include <console.h>
+#include <linux/bitops.h>
 #include <linux/delay.h>
 
 #include <gdsys_fpga.h>