trace: [configure] rename CONFIG_*_TRACE into CONFIG_TRACE_*

Provides a more hierarchical view of the variable domain.

Also adds the CONFIG_TRACE_* variables for all backends.

[Stefan added missing 'test' in stap if statement]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 0ccfb28..ad4174f 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -180,7 +180,7 @@
 Output logs to @var{filename}.
 ETEXI
 
-#ifdef CONFIG_SIMPLE_TRACE
+#ifdef CONFIG_TRACE_SIMPLE
     {
         .name       = "trace-event",
         .args_type  = "name:s,option:b",
@@ -1354,7 +1354,7 @@
 @end table
 ETEXI
 
-#ifdef CONFIG_SIMPLE_TRACE
+#ifdef CONFIG_TRACE_SIMPLE
 STEXI
 @item info trace
 show contents of trace buffer