OMAP2/3: IRQ: ensure valid base address

Ensure valid base address during IRQ init.  Fixes compiler warning
about potential use of uninitialized variable.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/irq.c

@@ -194,14 +194,16 @@ void __init omap_init_irq(void)
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
-		unsigned long base;
+		unsigned long base = 0;
 		struct omap_irq_bank *bank = irq_banks + i;
 
 		if (cpu_is_omap24xx())
 			base = OMAP24XX_IC_BASE;
 		else if (cpu_is_omap34xx())
 			base = OMAP34XX_IC_BASE;
 
+		BUG_ON(!base);
+
 		/* Static mapping, never released */
 		bank->base_reg = ioremap(base, SZ_4K);
 		if (!bank->base_reg) {