ACPI: property: Unify integer value reading functions

Unify functions reading ACPI property integer values into a single macro
using C99 _Generic().

Also use size_t for the counter instead of int.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>