[AVR32] Implement stacktrace support

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index b108dd8..599ec16 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -24,6 +24,9 @@
 config GENERIC_HARDIRQS
 	def_bool y
 
+config STACKTRACE_SUPPORT
+	def_bool y
+
 config HARDIRQS_SW_RESEND
 	def_bool y