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/gpio/mxs_gpio.c b/drivers/gpio/mxs_gpio.c
index 3094f1c..815339a 100644
--- a/drivers/gpio/mxs_gpio.c
+++ b/drivers/gpio/mxs_gpio.c
@@ -9,6 +9,7 @@
 #include <common.h>
 #include <log.h>
 #include <malloc.h>
+#include <linux/bitops.h>
 #include <linux/errno.h>
 #include <asm/io.h>
 #include <asm/arch/iomux.h>