panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I')

This taint flag will initially be used when warning about invalid ACPI
DMAR tables.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --cc Documentation/oops-tracing.txt
Simple merge

diff --cc include/linux/kernel.h
Simple merge

diff --cc kernel/panic.c
Simple merge