sparseirq: make some func to be used with genirq

Impact: clean up sparseirq fallout on random.c

Ingo suggested to change some ifdef from SPARSE_IRQ to GENERIC_HARDIRQS
so we could some #ifdef later if all arch support genirq

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 7c13581..a778918 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -558,7 +558,7 @@
 	unsigned dont_count_entropy:1;
 };
 
-#ifndef CONFIG_SPARSE_IRQ
+#ifndef CONFIG_GENERIC_HARDIRQS
 
 static struct timer_rand_state *irq_timer_state[NR_IRQS];