Clarify that the CDMA situation is AOSP-specific

Change-Id: Icbf01e2209d48d3fad4f8e289457ef6db00d5d9a
diff --git a/src/source/building-devices.md b/src/source/building-devices.md
index 0f7891d..443970a 100644
--- a/src/source/building-devices.md
+++ b/src/source/building-devices.md
@@ -43,7 +43,7 @@
 obsolete, were experimental and unsupported in froyo, and can't be used with
 newer versions of the Android Open-Source Project.
 
-No CDMA devices are supported.
+No CDMA devices are supported in the Android Open-Source Project.
 
 ## Building fastboot and adb ##