metag: Fix METAG Kconfig symbol select ordering

Commit d1a1dc0b (consolidate per-arch stack overflow debugging
options) broke the ordering of the selects in arch/metag/Kconfig by
adding select HAVE_DEBUG_STACKOVERFLOW at the end. Move it to the right
place.
Signed-off-by: James Hogan <james.hogan@imgtec.com>

arch/metag/Kconfig

@@ -9,6 +9,7 @@ config METAG
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_C_RECORDMCOUNT
 	select HAVE_DEBUG_KMEMLEAK
+	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
@@ -29,7 +30,6 @@ config METAG
 	select OF
 	select OF_EARLY_FLATTREE
 	select SPARSE_IRQ
-	select HAVE_DEBUG_STACKOVERFLOW
 
 config STACKTRACE_SUPPORT
 	def_bool y