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/ddr/altera/sdram_gen5.c b/drivers/ddr/altera/sdram_gen5.c
index ba588e9..1360bd0 100644
--- a/drivers/ddr/altera/sdram_gen5.c
+++ b/drivers/ddr/altera/sdram_gen5.c
@@ -15,6 +15,7 @@
 #include <asm/arch/reset_manager.h>
 #include <asm/arch/sdram.h>
 #include <asm/arch/system_manager.h>
+#include <asm/bitops.h>
 #include <asm/io.h>
 #include <dm/device_compat.h>