add a comment, reorder config stuff

Config.in

@@ -35,9 +35,15 @@ source "target/config/Config.in.arm"
 source "target/config/Config.in.x86"
 source "target/config/Config.in.qemu"
 source "target/config/Config.in.kernelversion"
-source "target/config/Config.in.libc"
 source "target/config/Config.in.toolchain"
+
+comment "changes made below do not require make cleandir after reconfiguration"
+menu "Target configuration"
 source "target/config/Config.in.qemuopts"
+source "target/config/Config.in.libc"
+source "target/config/Config.in.target"
+endmenu
+
 source "target/config/Config.in"
 
 menu "Package collection"
@@ -102,5 +108,4 @@ depends on !ADK_CHOOSE_TARGET_ARCH && !ADK_CHOOSE_TARGET_SYSTEM
 source "target/linux/Config.in"
 endmenu
 
-source "target/config/Config.in.target"
 source "target/config/Config.in.adk"