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/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c
index 3886614..1cd8866 100644
--- a/drivers/watchdog/mt7621_wdt.c
+++ b/drivers/watchdog/mt7621_wdt.c
@@ -12,6 +12,7 @@
 #include <common.h>
 #include <dm.h>
 #include <wdt.h>
+#include <linux/bitops.h>
 #include <linux/io.h>
 
 DECLARE_GLOBAL_DATA_PTR;