Add Nvidia enhancements soong flag

Change-Id: I1bec17d2457944350dcb5a22c6d571d3ace913a7
diff --git a/build/soong/android/variable.go b/build/soong/android/variable.go
index cfa5c7d..c2bb782 100644
--- a/build/soong/android/variable.go
+++ b/build/soong/android/variable.go
@@ -12,6 +12,9 @@
 	Uses_generic_camera_parameter_library struct {
 		Srcs []string
 	}
+	Uses_nvidia_enhancements struct {
+		Cppflags []string
+	}
 	Uses_qcom_bsp_legacy struct {
 		Cppflags []string
 	}
@@ -27,6 +30,7 @@
 	Specific_camera_parameter_library  *string `json:",omitempty"`
 	Target_shim_libs  *string `json:",omitempty"`
 	Uses_generic_camera_parameter_library  *bool `json:",omitempty"`
+	Uses_nvidia_enhancements  *bool `json:",omitempty"`
 	Uses_qcom_bsp_legacy  *bool `json:",omitempty"`
 	Uses_qti_camera_device  *bool `json:",omitempty"`
 }