HiresTextures: Support loading BC7 (BPTC) from DDS files

Source/Core/VideoCommon/VideoConfig.cpp

@@ -38,6 +38,7 @@ VideoConfig::VideoConfig()
   backend_info.bSupportsMultithreading = false;
   backend_info.bSupportsInternalResolutionFrameDumps = false;
   backend_info.bSupportsST3CTextures = false;
+  backend_info.bSupportsBPTCTextures = false;
 
   bEnableValidationLayer = false;
   bBackendMultithreading = true;