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/arch/arm/include/asm/arch-rockchip/ddr_rk3368.h b/arch/arm/include/asm/arch-rockchip/ddr_rk3368.h
index 82234cf..40cdcf4 100644
--- a/arch/arm/include/asm/arch-rockchip/ddr_rk3368.h
+++ b/arch/arm/include/asm/arch-rockchip/ddr_rk3368.h
@@ -6,6 +6,10 @@
 #ifndef __ASM_ARCH_DDR_RK3368_H__
 #define __ASM_ARCH_DDR_RK3368_H__
 
+#ifndef __ASSEMBLY__
+#include <linux/bitops.h>
+#endif
+
 /*
  * The RK3368 DDR PCTL differs from the incarnation in the RK3288 only
  * in a few details. Most notably, it has an additional field to track