[ARM] latencytop support

Available for !SMP only at the moment.

From Russell:

|Basically, if a thread is running on a CPU, thread_saved_fp() is invalid.
|So, the question is: what guarantees do we have here that 'tsk' is not
|running on another CPU?

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Tested-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b786e68..a91b9ac 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -84,6 +84,11 @@
 	bool
 	default y
 
+config HAVE_LATENCYTOP_SUPPORT
+	bool
+	depends on !SMP
+	default y
+
 config LOCKDEP_SUPPORT
 	bool
 	default y