i5100_edac: add fault injection code

Add fault injection based on information datasheet for i5100, see 1. In
addition to the i5100 datasheet some missing information on injection
functions where found through experimentation and the i7300 datasheet,
see 2.

[1] Intel 5100 Memory Controller Hub Chipset
    Doc.Nr: 318378
    http://www.intel.com/content/dam/doc/datasheet/5100-
    memory-controller-hub-chipset-datasheet.pdf

[2] Intel 7300 Chipset MemoryController Hub (MCH)
    Doc.Nr: 318082
	http://www.intel.com/assets/pdf/datasheet/318082.pdf

Signed-off-by: Niklas Söderlund <niklas.soderlund@ericsson.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>