qemu component: update conditional sections to buildout2-style.

s.r.cmmi 0.2.0 switched to buildout2-style, so we follow.
In the meantime, use a fixed target-list if it proper conditional
section is not supported.

component/qemu-kvm/buildout.cfg

@@ -20,6 +20,7 @@ md5sum = b56e73bdcfdb214d5c68e13111aca96f
 depends =
   ${libpng:so_version}
 configure-options =
+  --target-list=x86_64-softmmu
   --enable-system
   --with-system-pixman
   --disable-sdl
@@ -41,12 +42,13 @@ environment =
   PKG_CONFIG_PATH=${gnutls:location}/lib/pkgconfig:${glib:location}/lib/pkgconfig:${pixman:location}/lib/pkgconfig
   LDFLAGS=-L${pixman:location}/lib -Wl,-rpath=${pixman:location}/lib
 
-[amd64-linux-kvm]
+# The following is only available in buildout2, which we don't use yet.
+[kvm-bits64]
 configure-options =
   --target-list=x86_64-softmmu
   ${kvm:configure-options}
 
-[x86-linux-kvm]
+[kvm-bits32]
 configure-options =
   --target-list=i386-softmmu
   ${kvm:configure-options}