cherrypick 76bd108d from master. do not merge.

Change-Id: Ibb677f286b54a9dd593301a0f8b194d3b2dc58d1
SDK: update SDK to API 15
diff --git a/sdk/usbdriver_source.properties b/sdk/usbdriver_source.properties
index 3f9484b..c55310e 100755
--- a/sdk/usbdriver_source.properties
+++ b/sdk/usbdriver_source.properties
@@ -1,4 +1,4 @@
-Pkg.Revision=4

+Pkg.Revision=5

 Archive.Os=WINDOWS

 Archive.Arch=ANY

 Extra.Path=usb_driver