[ACPI] Suspend to RAM fix

Free some RAM before entering S3 so that upon
resume we can be sure early allocations will succeed.

http://bugzilla.kernel.org/show_bug.cgi?id=3469



Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>