ACPI / LPSS: override power state for LPSS DMA device

BugLink: http://bugs.launchpad.net/bugs/1602579

This is a third approach to workaround long standing issue with LPSS on
BayTrail. First one [1] was reverted since it didn't resolve the issue
comprehensively. Second one [2] was rejected by internal review.

The LPSS DMA controller does not have neither _PS0 nor _PS3 method. Moreover it
can be powered off automatically whenever the last LPSS device goes down. In
case of no power any access to the DMA controller will hang the system. The
behaviour is reproduced on some HP laptops based on Intel BayTrail [3,4] as
well as on ASuS T100TA transformer.

Power on the LPSS island through the registers accessible in a specific way.

[1] http://www.spinics.net/lists/linux-acpi/msg53963.html
[2] https://bugzilla.redhat.com/attachment.cgi?id=1066779&action=diff
[3] https://bugzilla.redhat.com/show_bug.cgi?id=1184273
[4] http://www.spinics.net/lists/dmaengine/msg01514.html



Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit eebb3e8d)
Signed-off-by: Hui Wang <hui.wang@canonical.com>

Conflicts:
	arch/x86/include/asm/iosf_mbi.h
[To fix the conflicts and guarantee the success of building after
 applying this patch, I copied _READ and _WRITE definitions from
 the commit 4077a387 into this patch].

Acked-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>