ghes_edac: Make it compliant with UEFI spec 2.3.1

ghes_edac: Make it compliant with UEFI spec 2.3.1

The UEFI spec defines the memory error types ans the bits that
validate each field on the memory error record, at
Appendix N om items N.2.5 (Memory Error Section) and
N.2.11 (Error Status). Make the error description compliant with
it, only showing the valid fields.

The EDAC error log is now properly reporting the error:

[  281.556854] mce: [Hardware Error]: Machine check events logged
[  281.557042] {2}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 0
[  281.557044] {2}[Hardware Error]: APEI generic hardware error status
[  281.557046] {2}[Hardware Error]: severity: 2, corrected
[  281.557048] {2}[Hardware Error]: section: 0, severity: 2, corrected
[  281.557050] {2}[Hardware Error]: flags: 0x01
[  281.557052] {2}[Hardware Error]: primary
[  281.557053] {2}[Hardware Error]: section_type: memory error
[  281.557055] {2}[Hardware Error]: error_status: 0x0000000000000400
[  281.557056] {2}[Hardware Error]: node: 3
[  281.557057] {2}[Hardware Error]: card: 0
[  281.557058] {2}[Hardware Error]: module: 1
[  281.557059] {2}[Hardware Error]: device: 0
[  281.557061] {2}[Hardware Error]: error_type: 18, unknown
[  281.557067] EDAC DEBUG: ghes_edac_report_mem_error: error validation_bits: 0x000040b9
[  281.557084] EDAC MC0: 1 CE reserved error (18) on unknown label (node:3 card:0 module:1 page:0x0 offset:0x0 grain:0 syndrome:0x0 - status(0x0000000000000400): Storage error in DRAM memory)

Tested on a 4 CPUs E5-4650 Sandy Bridge machine.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>