pm+acpi-3.19-fin

This is a revert of an ACPI Low-power Subsystem (LPSS) driver change
that was supposed to improve power management of the LPSS DMA controller,
but introduced more serious problems.

Since fixing them turns out to be non-trivial, it is better to revert
the commit in question at this point and try to fix the original issue
differently in the next cycle.

/