When the Lenovo Ideapad S10-3 is booted with HT enabled,
it hits a boot hang in the intel_idle driver.

This occurs when entering ATM-C4 for the first time,
unless BM_STS is first cleared.

acpi_idle doesn't see this because it first checks
and clears BM_STS, but it would hit the same hang
if that check were disabled.

http://bugs.meego.com/show_bug.cgi?id=7093
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/634702Signed-off-by: NLen Brown <len.brown@intel.com>