ARC: More code beautification with IS_ENABLED()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/kernel/irq.c

@@ -38,15 +38,9 @@ void __cpuinit arc_init_IRQ(void)
 	write_aux_reg(AUX_IENABLE, 0);
 
        /* setup any high priority Interrupts (Level2 in ARCompact jargon) */
-#ifdef CONFIG_ARC_IRQ3_LV2
-	level_mask |= (1 << 3);
-#endif
-#ifdef CONFIG_ARC_IRQ5_LV2
-	level_mask |= (1 << 5);
-#endif
-#ifdef CONFIG_ARC_IRQ6_LV2
-	level_mask |= (1 << 6);
-#endif
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ3_LV2) << 3;
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ5_LV2) << 5;
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ6_LV2) << 6;
 
 	if (level_mask) {
 		pr_info("Level-2 interrupts bitset %x\n", level_mask);