ACPI: restore comment justifying 'extra' P_LVLx access
ACPI: restore comment justifying 'extra' P_LVLx access

While trying to look for superfluous I/O accesses that can be optimized
away, I stumbled upon this ACPI sleep I/O access and couldn't figure out
why the hell this dummy op was necessary.
After more than one hour of internet research, I had collected a sufficient
number of documents (among those very old kernel versions) that finally
told me what this dummy read was about: STPCLK# doesn't get asserted in time
on (some) chipsets, which is why we need to have a dummy I/O read to delay
further instruction processing until the CPU is fully stopped.

Signed-off-by: Andreas Mohr <dbd122ef7b6a09ffecf5db9c9296320f3c94e707@lisas.de>
Signed-off-by: Len Brown <b060cfa1096cc6e8be83699ddb4ed8a77dd63af5@intel.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs