acpi - Catch infinite parser recursions

acpi - Catch infinite parser recursions

* Instrument AcpiPsParseLoop() and limited recursion depth to 5.
  Generally speaking this loop can call a very deep stack of
  routines and eat up the kernel stack.  A depth limit of 5 might
  be a bit too low, but it doesn't take much more to blow up
  our current 16KB kernel stack.

  This prevents the kernel from double-faulting on excessively bad
  AML.

* Works around reported boot-time double-faults on some laptops.