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/zynq_gem.c b/drivers/net/zynq_gem.c
index 28cef3b..412daf7 100644
--- a/drivers/net/zynq_gem.c
+++ b/drivers/net/zynq_gem.c
@@ -28,6 +28,7 @@
 #include <asm/arch/hardware.h>
 #include <asm/arch/sys_proto.h>
 #include <dm/device_compat.h>
+#include <linux/bitops.h>
 #include <linux/err.h>
 #include <linux/errno.h>