sh: Configurable timer IRQ.

All of the various CPU subtypes currently hardcode TIMER_IRQ,
switch this to a config option in the few places we need this.

This allows further removal of hardcoded IRQ headers..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/timers/timer-mtu2.c b/arch/sh/kernel/timers/timer-mtu2.c
index 045b2ab..92c98b5 100644
--- a/arch/sh/kernel/timers/timer-mtu2.c
+++ b/arch/sh/kernel/timers/timer-mtu2.c
@@ -167,7 +167,7 @@
 	u8 tmp;
 	unsigned long interval;
 
-	setup_irq(TIMER_IRQ, &mtu2_irq);
+	setup_irq(CONFIG_SH_TIMER_IRQ, &mtu2_irq);
 
 	mtu2_clk1.parent = clk_get("module_clk");