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/timer/mpc83xx_timer.c b/drivers/timer/mpc83xx_timer.c
index 186fe2b..ad8bb28 100644
--- a/drivers/timer/mpc83xx_timer.c
+++ b/drivers/timer/mpc83xx_timer.c
@@ -15,6 +15,7 @@
 #include <timer.h>
 #include <watchdog.h>
 #include <asm/ptrace.h>
+#include <linux/bitops.h>
 
 DECLARE_GLOBAL_DATA_PTR;