ia64: add support for TIF_NOTIFY_SIGNAL

[ Upstream commit b269c229 ]

Wire up TIF_NOTIFY_SIGNAL handling for ia64.

Cc: linux-ia64@vger.kernel.org
[axboe: added fixes from Mike Rapoport <rppt@kernel.org>]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>