stable/for-linus-3.4-tag-two

 * Add fast-EOI acking of interrupts (clear a bit instead of hypercall)
And bug-fixes:
 * Fix CPU bring-up code missing a call to notify other subsystems.
 * Fix reading /sys/hypervisor even if PVonHVM drivers are not loaded.
 * In Xen ACPI processor driver: remove too verbose WARN messages, fix up
   the Kconfig dependency to be a module by default, and add dependency on
   CPU_FREQ.
 * Disable CPU frequency drivers from loading when booting under Xen
   (as we want the Xen ACPI processor to be used instead).
 * Cleanups in tmem code.