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/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c
index 1dc7ee9..cb04f56 100644
--- a/drivers/cpu/riscv_cpu.c
+++ b/drivers/cpu/riscv_cpu.c
@@ -10,6 +10,7 @@
 #include <log.h>
 #include <dm/device-internal.h>
 #include <dm/lists.h>
+#include <linux/bitops.h>
 
 DECLARE_GLOBAL_DATA_PTR;