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/i2c/at91_i2c.h b/drivers/i2c/at91_i2c.h
index 87f02bf..3915af8 100644
--- a/drivers/i2c/at91_i2c.h
+++ b/drivers/i2c/at91_i2c.h
@@ -1,6 +1,7 @@
 #ifndef _AT91_I2C_H
 #define _AT91_I2C_H
 
+#include <linux/bitops.h>
 #define	TWI_CR_START		BIT(0)	/* Send a Start Condition */
 #define	TWI_CR_MSEN		BIT(2)	/* Master Transfer Enable */
 #define	TWI_CR_STOP		BIT(1)	/* Send a Stop Condition */