tracing, x86: clean up FUNCTION_RET_TRACER Kconfig

Impact: cleanup

move FUNCTION_RET_TRACER to the X86 select section, where we have all the
other options.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/Kconfig

@@ -11,7 +11,6 @@ config 64BIT
 
 config X86_32
 	def_bool !64BIT
-	select HAVE_FUNCTION_RET_TRACER
 
 config X86_64
 	def_bool 64BIT
@@ -30,6 +29,7 @@ config X86
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FUNCTION_TRACER
+	select HAVE_FUNCTION_RET_TRACER if X86_32
 	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
 	select HAVE_ARCH_KGDB if !X86_VOYAGER