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/Marvell/db-88f6820-amc/db-88f6820-amc.c b/board/Marvell/db-88f6820-amc/db-88f6820-amc.c
index f225f46..60ce940 100644
--- a/board/Marvell/db-88f6820-amc/db-88f6820-amc.c
+++ b/board/Marvell/db-88f6820-amc/db-88f6820-amc.c
@@ -12,6 +12,7 @@
 #include <asm/io.h>
 #include <asm/arch/cpu.h>
 #include <asm/arch/soc.h>
+#include <linux/bitops.h>
 
 #include "../drivers/ddr/marvell/a38x/ddr3_init.h"
 #include <../serdes/a38x/high_speed_env_spec.h>