x86: Move include of bitops out of ACPI region

At present linux/bitops.h is included in ACPI code. This is not needed and
can cause a problem in fls64.h since BITS_PER_LONG is not defined. Move
the #include into the part not used by ACPI.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>