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/stm32_timer.c b/drivers/timer/stm32_timer.c
index 76d99a2..c57fa3f 100644
--- a/drivers/timer/stm32_timer.c
+++ b/drivers/timer/stm32_timer.c
@@ -10,6 +10,7 @@
 #include <fdtdec.h>
 #include <timer.h>
 #include <dm/device_compat.h>
+#include <linux/bitops.h>
 
 #include <asm/io.h>