ACPI: C-States: bm_activity improvements

ACPI: C-States: bm_activity improvements

Do not assume there was bus mastering activity if the idle handler didn't get
called, as there's only reason to not enter C3-type sleep if there is bus
master activity going on.  Only for the "promotion" into C3-type sleep bus
mastering activity is taken into account, and there only current bus mastering
activity, and not pure guessing should lead to the decision on whether to
enter C3-type sleep or not.

Also, as bm_activity is a jiffy-based bitmask (bit 0: bus mastering activity
during this juffy, bit 31: bus mastering activity 31 jiffies ago), fix the
setting of bit 0, as it might be called multiple times within one jiffy.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>