Use headers in the external folder prior to the system Vulkan headers
diff --git a/build-qnx/common.mk b/build-qnx/common.mk
index c9379ca..8a23ea6 100644
--- a/build-qnx/common.mk
+++ b/build-qnx/common.mk
@@ -10,6 +10,7 @@
 ICD_ROOT=$(CURDIR)/../../../..
 
 EXTRA_INCVPATH+=$(ICD_ROOT)/build_qnx
+EXTRA_INCVPATH+=$(ICD_ROOT)/external/Vulkan-Headers/include
 
 EXTRA_SRCVPATH+=$(ICD_ROOT)/loader
 EXTRA_SRCVPATH+=$(ICD_ROOT)/loader/generated