irq: Always define devm_{request_threaded,free}_irq()

This is only needed for 3.11, as s390 has now been changed to use the
generic IRQ code upstream.

These functions are currently defined only if CONFIG_GENERIC_HARDIRQS
is enabled.  But they are still needed on s390 which has its own IRQ
management.

References: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=s390&ver=3.11%7Erc4-1%7Eexp1&stamp=1376009959
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2 files changed