vendor/bliss: Add Nvidia enhancements soong flag

Change-Id: I1bec17d2457944350dcb5a22c6d571d3ace913a7
diff --git a/build/soong/android/variable.go b/build/soong/android/variable.go
index a814b74..95df5d1 100644
--- a/build/soong/android/variable.go
+++ b/build/soong/android/variable.go
@@ -55,6 +55,10 @@
 		Cppflags []string
 		Shared_libs []string
 	}
+	
+	Uses_nvidia_enhancements struct {
+		Cppflags []string
+	}
 }
 
 type ProductVariables struct {
@@ -75,4 +79,5 @@
 	Target_uses_eigen       *bool `json:",omitempty"`
 	Target_shim_libs  *string `json:",omitempty"`
 	Uses_qti_camera_device  *bool `json:",omitempty"`
+	Uses_nvidia_enhancements  *bool `json:",omitempty"`
 }