build: Define QC_OPEN_PATH

All references in sm7250 repos point to the correct location
if we simply define QC_OPEN_PATH as vendor/qcom/opensource

Change-Id: Ibb580230212a08c73a251c88630217b192979eb4
diff --git a/build/core/qcom_target.mk b/build/core/qcom_target.mk
index 6d78cdb..395f6cd 100644
--- a/build/core/qcom_target.mk
+++ b/build/core/qcom_target.mk
@@ -23,4 +23,8 @@
 PRODUCT_CFI_INCLUDE_PATHS += \
     hardware/qcom-caf/wlan/qcwcn/wpa_supplicant_8_lib
 
+else
+
+QC_OPEN_PATH := vendor/qcom/opensource
+
 endif