avr32: Build fix for CONFIG_BUG=n

Don't include the BUG trap handling code when CONFIG_BUG is not set.
This fixes allnoconfig.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
diff --git a/arch/avr32/kernel/traps.c b/arch/avr32/kernel/traps.c
index cf6f686..b835c4c 100644
--- a/arch/avr32/kernel/traps.c
+++ b/arch/avr32/kernel/traps.c
@@ -178,6 +178,7 @@
 	return 0;
 }
 
+#ifdef CONFIG_BUG
 int is_valid_bugaddr(unsigned long pc)
 {
 	unsigned short opcode;
@@ -189,6 +190,7 @@
 
 	return opcode == AVR32_BUG_OPCODE;
 }
+#endif
 
 asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
 {
@@ -197,6 +199,7 @@
 	void __user *pc;
 	long code;
 
+#ifdef CONFIG_BUG
 	if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
 		enum bug_trap_type type;
 
@@ -211,6 +214,7 @@
 			die("Kernel BUG", regs, SIGKILL);
 		}
 	}
+#endif
 
 	local_irq_enable();