Define the Windows SDK pre-requisite module list.

Change-Id: I08fc98f2e1046ec1f115fc9c0371d1b07eb47c97
diff --git a/build/windows_sdk_tools.mk b/build/windows_sdk_tools.mk
index 477adac..5ddca7d 100644
--- a/build/windows_sdk_tools.mk
+++ b/build/windows_sdk_tools.mk
@@ -3,6 +3,8 @@
 # This makefile is included by development/build/tools/windows_sdk.mk
 # to device which tools we want to build from the sdk.git project.
 
+# Define the list of tool-dependent modules to build for the Windows SDK.
+# All these will be build using USE_MINGW=1
 WIN_SDK_TARGETS := \
 	avdlauncher \
 	emulator \
@@ -24,3 +26,7 @@
 	libEGL_translator
 endif
 
+# Define the list of tool-dependent modules requisites needed
+# for the Windows SDK. These will be built using HOST_OS=linux.
+WIN_SDK_BUILD_PREREQ :=
+