[llvm] [NFC][RISCV] Move Zvfbf* relative stuffs to RISCVInstrInfoZvfbf.td (PR #159619)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-win-fast` running on `as-builder-3` while building `llvm` at step 6 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/2/builds/34265

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

```
Step 6 (build-unified-tree) failure: build (failure)
...
[979/4305] Building CXX object utils\TableGen\Common\CMakeFiles\obj.LLVMTableGenCommon.dir\DAGISelMatcher.cpp.obj
[980/4305] Building CXX object lib\Frontend\OpenACC\CMakeFiles\LLVMFrontendOpenACC.dir\ACC.cpp.obj
[981/4305] Building CXX object utils\TableGen\Common\CMakeFiles\obj.LLVMTableGenCommon.dir\SubtargetFeatureInfo.cpp.obj
[982/4305] Building CXX object utils\TableGen\Common\CMakeFiles\obj.LLVMTableGenCommon.dir\PredicateExpander.cpp.obj
[983/4305] Building CXX object utils\TableGen\Common\CMakeFiles\obj.LLVMTableGenCommon.dir\VarLenCodeEmitterGen.cpp.obj
[984/4305] Building CXX object utils\TableGen\Common\CMakeFiles\obj.LLVMTableGenCommon.dir\CodeGenRegisters.cpp.obj
[985/4305] Building CXX object utils\TableGen\CMakeFiles\llvm-tblgen.dir\X86FoldTablesEmitter.cpp.obj
[986/4305] Building CXX object utils\TableGen\Common\CMakeFiles\obj.LLVMTableGenCommon.dir\Utils.cpp.obj
[987/4305] Linking CXX static library lib\LLVMFrontendOpenACC.lib
[988/4305] Building RISCVTargetParserDef.inc...
FAILED: include/llvm/TargetParser/RISCVTargetParserDef.inc C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/build/include/llvm/TargetParser/RISCVTargetParserDef.inc 
cmd.exe /C "cd /D C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\build\include\llvm\TargetParser && C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\build\bin\llvm-min-tblgen.exe -gen-riscv-target-def -IC:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/include/llvm/TargetParser -IC:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/lib/Target/RISCV -IC:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/build/include -IC:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/include --long-string-literals=0 C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/lib/Target/RISCV/RISCV.td --write-if-changed -o C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/build/include/llvm/TargetParser/RISCVTargetParserDef.inc"
Included from C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/lib/Target/RISCV/RISCV.td:36:
Included from C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/lib/Target/RISCV\RISCVInstrInfo.td:2344:
Included from C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/lib/Target/RISCV\RISCVInstrInfoV.td:1842:
C:/buildbot/as-builder-3/llvm-clang-x86_64-win-fast/llvm-project/llvm/lib/Target/RISCV\RISCVInstrInfoZvfbf.td:39:19: error: Variable not defined: 'HasStdExtZvfbfmin'
let Predicates = [HasStdExtZvfbfmin] in {
                  ^
[989/4305] Linking CXX static library lib\LLVMTableGenCommon.lib
[990/4305] Linking CXX executable bin\llvm-tblgen.exe
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/159619