RFR: 8316859: RISC-V: Disable detection of V through HWCAP

[Ludovic Henry]

Some dev boards only support RVV version 0.7, while the OpenJDK only supports RVV version 1.0. These two versions are not compatible with each other. Given the V bit is set through HWCAP on some custom kernels, regardless of the version, it can lead to generating V instructions on boards that don't support RVV version 1.0 (ex: Sipeed LicheePi), leading to a SIGILL.

That is an acceptable workaround as only Linux Kernel v6.5+ supports V, and that version already support hwprobe anyway

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Commit messages:
 - 8316859: RISC-V: Disable detection of V through HWCAP

Changes: https://git.openjdk.org/jdk/pull/15898/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15898&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316859
  Stats: 13 lines in 1 file changed: 10 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/15898.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15898/head:pull/15898

PR: https://git.openjdk.org/jdk/pull/15898