UPSTREAM: alpha: add support for TIF_NOTIFY_SIGNAL

[ Upstream commit 5a9a8897 ]

Wire up TIF_NOTIFY_SIGNAL handling for alpha.

Cc: linux-alpha@vger.kernel.org
Change-Id: I44b3be73e9a332bfc92b8f5c34426770c9642dae
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 30b78a17)
Bug: 268174392
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>