Move CodeGen cuda.h to Inputs from include (llvm#134706)

Mirrors the behavior of CodeGenCUDA directory and the location of other
.h files in CodeGen.

Author: calewis

clang/test/CodeGen/include/cuda.h renamed to clang/test/CodeGen/Inputs/cuda.h

@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -triple nvptx-unknown-unknown -fcuda-is-device -O3 -o - %s -emit-llvm | FileCheck %s
 // RUN: %clang_cc1 -triple nvptx64-unknown-unknown -fcuda-is-device -O3 -o - %s -emit-llvm | FileCheck %s
-#include "include/cuda.h"
+#include "Inputs/cuda.h"
 
 #include "__clang_cuda_texture_intrinsics.h"