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/include/virtio.h b/include/virtio.h
index 46f9efb..10a9c07 100644
--- a/include/virtio.h
+++ b/include/virtio.h
@@ -20,6 +20,7 @@
 #ifndef __VIRTIO_H__
 #define __VIRTIO_H__
 
+#include <linux/bitops.h>
 #include <linux/bug.h>
 #define VIRTIO_ID_NET		1 /* virtio net */
 #define VIRTIO_ID_BLOCK		2 /* virtio block */