[libc] Remove 'llvm-gpu-none' directory from build (#82816)

Summary:
This directory is leftover from when we handled both AMDGPU and NVPTX in
the same build and merged them into a pseudo triple. Now the only thing
it contains is the RPC server header. This gets rid of it, but now that
it's in the base install directory we should make it clear that it's an
LLVM libc header.
GitOrigin-RevId: 1a2ecbb3980a3005c2027eb5b69bbbe32c9c8294
diff --git a/libomptarget/plugins-nextgen/common/src/RPC.cpp b/libomptarget/plugins-nextgen/common/src/RPC.cpp
index cb6a508..05ae5ac 100644
--- a/libomptarget/plugins-nextgen/common/src/RPC.cpp
+++ b/libomptarget/plugins-nextgen/common/src/RPC.cpp
@@ -12,14 +12,8 @@
 
 #include "PluginInterface.h"
 
-// This header file may be present in-tree or from an LLVM installation. The
-// installed version lives alongside the GPU headers so we do not want to
-// include it directly.
-#if __has_include(<gpu-none-llvm/rpc_server.h>)
-#include <gpu-none-llvm/rpc_server.h>
-#elif defined(LIBOMPTARGET_RPC_SUPPORT)
-// Just pull this out of the source if available.
-#include "rpc_server.h"
+#if defined(LIBOMPTARGET_RPC_SUPPORT)
+#include "llvmlibc_rpc_server.h"
 #endif
 
 using namespace llvm;