ACPICA: Add new statistics interface.

This patch ports new counters and statistics interface, already
implemented in ACPICA upstream, to Linux.  That helps to reduce
source code differences between Linux and ACPICA upstream.

[rjw: Changelog]
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>