[llvm] AMDGPU: Remove triple field from subtarget (PR #164208)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `arc-builder` running on `arc-worker` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/3/builds/23656

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: ExecutionEngine/JITLink/x86-64/MachO-duplicate-local.test' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 1
/buildbot/worker/arc-folder/build/bin/yaml2obj /buildbot/worker/arc-folder/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/MachO-duplicate-local.test -o /buildbot/worker/arc-folder/build/test/ExecutionEngine/JITLink/x86-64/Output/MachO-duplicate-local.test.tmp
# executed command: /buildbot/worker/arc-folder/build/bin/yaml2obj /buildbot/worker/arc-folder/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/MachO-duplicate-local.test -o /buildbot/worker/arc-folder/build/test/ExecutionEngine/JITLink/x86-64/Output/MachO-duplicate-local.test.tmp
# RUN: at line 2
/buildbot/worker/arc-folder/build/bin/llvm-jitlink -noexec -show-graphs='.*' /buildbot/worker/arc-folder/build/test/ExecutionEngine/JITLink/x86-64/Output/MachO-duplicate-local.test.tmp | /buildbot/worker/arc-folder/build/bin/FileCheck /buildbot/worker/arc-folder/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/MachO-duplicate-local.test
# executed command: /buildbot/worker/arc-folder/build/bin/llvm-jitlink -noexec '-show-graphs=.*' /buildbot/worker/arc-folder/build/test/ExecutionEngine/JITLink/x86-64/Output/MachO-duplicate-local.test.tmp
# .---command stderr------------
# | llvm-jitlink error: Cannot allocate memory
# `-----------------------------
# error: command failed with exit status: 1
# executed command: /buildbot/worker/arc-folder/build/bin/FileCheck /buildbot/worker/arc-folder/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/MachO-duplicate-local.test
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /buildbot/worker/arc-folder/build/bin/FileCheck /buildbot/worker/arc-folder/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/MachO-duplicate-local.test
# `-----------------------------
# error: command failed with exit status: 2

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/164208