x86/mce: Include a MCi_MISC value in faked mce logs

When BIOS reports memory errors to Linux using the ACPI/APEI
error reporting method Linux creates a "struct mce" to pass
to the normal reporting code path.

The constructed record doesn't include a value for the "misc"
field of the structure, and so mce_usable_address() says this
record doesn't include a valid address.

Net result is that functions like uc_decode_notifier() will
just ignore this record instead of taking action to offline
a page.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210527222846.931851-1-tony.luck@intel.com