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/atmel_pio4.c b/drivers/gpio/atmel_pio4.c
index a3f5e7a..455944d 100644
--- a/drivers/gpio/atmel_pio4.c
+++ b/drivers/gpio/atmel_pio4.c
@@ -12,6 +12,7 @@
 #include <malloc.h>
 #include <asm/arch/hardware.h>
 #include <asm/gpio.h>
+#include <linux/bitops.h>
 #include <mach/gpio.h>
 #include <mach/atmel_pio4.h>