ACPI, APEI, APEI supporting infrastructure

APEI stands for ACPI Platform Error Interface, which allows to report
errors (for example from the chipset) to the operating system. This
improves NMI handling especially. In addition it supports error
serialization and error injection.

For more information about APEI, please refer to ACPI Specification
version 4.0, chapter 17.

This patch provides some common functions used by more than one APEI
tables, mainly framework of interpreter for EINJ and ERST.

A machine readable language is defined for EINJ and ERST for OS to
execute, and so to drive the firmware to fulfill the corresponding
functions. The machine language for EINJ and ERST is compatible, so a
common framework is defined for them.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>