Clean up names in comments.

Author: Artem-B

llvm/include/llvm/Support/NVPTXAddrSpace.h

@@ -1,4 +1,4 @@
-//===---------------- AMDGPUAddrSpace.h -------------------------*- C++ -*-===//
+//===---------------- NVPTXAddrSpace.h -------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 //
 /// \file
-/// AMDGPU address space definition
+/// NVPTX address space definition
 ///
 //
 //===----------------------------------------------------------------------===//