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/drivers/net/ag7xxx.c b/drivers/net/ag7xxx.c
index 0fe140c..3b5d11f 100644
--- a/drivers/net/ag7xxx.c
+++ b/drivers/net/ag7xxx.c
@@ -16,6 +16,7 @@
 #include <malloc.h>
 #include <net.h>
 #include <asm/cache.h>
+#include <linux/bitops.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
 #include <linux/err.h>