irq_work, alpha: Fix up arch hooks

Commit e360adb ("irq_work: Add generic hardirq context
callbacks") fouled up the Alpha bit, not properly naming the
arch specific function that raises the 'self-IPI'.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: stable@kernel.org # 37+
Link: http://lkml.kernel.org/n/tip-gukh0txmql2l4thgrekzzbfy@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/alpha/kernel/time.c

@@ -91,7 +91,7 @@ DEFINE_PER_CPU(u8, irq_work_pending);
 #define test_irq_work_pending()      __get_cpu_var(irq_work_pending)
 #define clear_irq_work_pending()     __get_cpu_var(irq_work_pending) = 0
 
-void set_irq_work_pending(void)
+void arch_irq_work_raise(void)
 {
 	set_irq_work_pending_flag();
 }