[llvm] AMDGPU: Fix entry for mac in VGPR->AGPR MFMA table (PR #119693)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-out-of-tree` running on `linaro-flang-aarch64-out-of-tree` while building `llvm` at step 7 "build-flang-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/53/builds/9425

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

```
Step 7 (build-flang-unified-tree) failure: build (failure)
...
2.457 [29/3/2] Building CXX object lib/Common/CMakeFiles/FortranCommon.dir/Version.cpp.o
2.516 [28/3/3] Linking CXX static library lib/libFortranCommon.a
2.957 [22/8/4] Linking CXX executable unittests/Evaluate/logical.test
3.014 [22/7/5] Linking CXX executable unittests/Evaluate/integer.test
3.033 [22/6/6] Linking CXX executable unittests/Evaluate/real.test
4.100 [22/5/7] Linking CXX executable bin/f18-parse-demo
4.219 [22/4/8] Linking CXX executable bin/fir-lsp-server
6.701 [22/3/9] Linking CXX executable unittests/Evaluate/folding.test
6.774 [22/2/10] Linking CXX executable unittests/Evaluate/expression.test
51.132 [22/1/11] Building CXX object lib/Optimizer/Transforms/CMakeFiles/FIRTransforms.dir/CUFDeviceGlobal.cpp.o
FAILED: lib/Optimizer/Transforms/CMakeFiles/FIRTransforms.dir/CUFDeviceGlobal.cpp.o 
/usr/local/bin/c++ -DFLANG_INCLUDE_TESTS=1 -DFLANG_LITTLE_ENDIAN=1 -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/build_flang/lib/Optimizer/Transforms -I/home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/llvm-project/flang/lib/Optimizer/Transforms -I/home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/llvm-project/flang/include -I/home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/build_flang/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/llvm-project/mlir/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/build_llvm/tools/mlir/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/llvm-project/llvm/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/build_llvm/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/llvm-project/clang/include -isystem /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/build_llvm/tools/clang/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Werror -Wno-deprecated-copy -Wno-string-conversion -Wno-ctad-maybe-unsupported -Wno-unused-command-line-argument -Wstring-conversion           -Wcovered-switch-default -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17   -D_GNU_SOURCE -D_DEBUG -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/Optimizer/Transforms/CMakeFiles/FIRTransforms.dir/CUFDeviceGlobal.cpp.o -MF lib/Optimizer/Transforms/CMakeFiles/FIRTransforms.dir/CUFDeviceGlobal.cpp.o.d -o lib/Optimizer/Transforms/CMakeFiles/FIRTransforms.dir/CUFDeviceGlobal.cpp.o -c /home/tcwg-buildbot/worker/flang-aarch64-out-of-tree/llvm-project/flang/lib/Optimizer/Transforms/CUFDeviceGlobal.cpp
../llvm-project/flang/lib/Optimizer/Transforms/CUFDeviceGlobal.cpp:31:34: error: unused variable 'builtinPrefix' [-Werror,-Wunused-const-variable]
   31 | static constexpr llvm::StringRef builtinPrefix = "_QM__fortran_builtins";
      |                                  ^~~~~~~~~~~~~
1 error generated.
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/119693