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/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
index 0c43686..801d142 100644
--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -9,6 +9,7 @@
 #include <common.h>
 #include <dm.h>
 #include <dm/pinctrl.h>
+#include <linux/bitops.h>
 #include <linux/io.h>
 #include <linux/err.h>
 #include <mach/atmel_pio4.h>