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/board/freescale/mpc837xerdb/mpc837xerdb.c b/board/freescale/mpc837xerdb/mpc837xerdb.c
index 3fd2c5e..94cb93a 100644
--- a/board/freescale/mpc837xerdb/mpc837xerdb.c
+++ b/board/freescale/mpc837xerdb/mpc837xerdb.c
@@ -10,6 +10,7 @@
 #include <hwconfig.h>
 #include <i2c.h>
 #include <init.h>
+#include <asm/bitops.h>
 #include <asm/io.h>
 #include <asm/fsl_mpc83xx_serdes.h>
 #include <fdt_support.h>