While debugging a boot failure, the following unknown error record was
seen in the boot logs.

    <...>
    BERT: Error records from previous boot:
    [Hardware Error]: event severity: fatal
    [Hardware Error]:  Error 0, type: fatal
    [Hardware Error]:   section type: unknown, 81212a96-09ed-4996-9471-8d729c8e69ed
    [Hardware Error]:   section length: 0x290
    [Hardware Error]:   00000000: 00000001 00000000 00000000 00020002  ................
    [Hardware Error]:   00000010: 00020002 0000001f 00000320 00000000  ........ .......
    [Hardware Error]:   00000020: 00000000 00000000 00000000 00000000  ................
    [Hardware Error]:   00000030: 00000000 00000000 00000000 00000000  ................
    <...>

On further investigation, it was found that the error record with
UUID (81212a96-09ed-4996-9471-8d729c8e69ed) has been defined in the
UEFI Specification at least since v2.4 and has recently had additional
fields defined in v2.7 Section N.2.10 Firmware Error Record Reference.

Add support for parsing and printing the defined fields to give users
a chance to figure out what went wrong.
Signed-off-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Link: https://lore.kernel.org/r/20200512045502.3810339-1-punit1.agrawal@toshiba.co.jpSigned-off-by: Ard Biesheuvel <ardb@kernel.org>