Fix pdk build.

The pdk builds don't have access to development.

Change-Id: Ie7e9f8d24b788749481465311e64145e175b8c4f
diff --git a/target/product/sdk.mk b/target/product/sdk.mk
index 102651b..8f29b8c 100644
--- a/target/product/sdk.mk
+++ b/target/product/sdk.mk
@@ -65,8 +65,8 @@
 
 
 # Define the host tools and libs that are parts of the SDK.
-include sdk/build/product_sdk.mk
-include development/build/product_sdk.mk
+-include sdk/build/product_sdk.mk
+-include development/build/product_sdk.mk
 
 # audio libraries.
 PRODUCT_PACKAGES += \