sparc64: Add save_stack_trace_tsk().

And this allows us to indicate HAVE_LATENCYTOP_SUPPORT.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 10945c3..e162535 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -72,6 +72,10 @@
 	bool
 	default y if SPARC64
 
+config HAVE_LATENCYTOP_SUPPORT
+	bool
+	default y if SPARC64
+
 config AUDIT_ARCH
 	bool
 	default y if SPARC64