PCI-Express AER implemetation: aer howto document

PCI-Express AER (Advanced Error Reporting) provides more robust error reporting.
The series of patches enable kernel support to AER.

The initial patches were written by Tom Long Nguyen. I ported them to the kernel
2.6.18-rc3. Many thanks to Rajesh Shah and Narayanan Chandramouli for their great
review comments and testing help.

Patch 1 consists of the pciaer-howto.txt document.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>