[riscv-port-jdk17u:riscv-port] RFR: 8297697: RISC-V: Add support for SATP mode detection

[Gui Cao]

Hi,
Please review this backport to riscv-port-jdk17u.
Backport of [JDK-8297697](https://bugs.openjdk.org/browse/JDK-8297697), and [JDK-8301067](https://bugs.openjdk.org/browse/JDK-8301067). JDK-8301067 only modifies the log description information introduced by JDK-8297697.

After this patch, If it is an unsupported satp.mode , the message will be as follows:

root at qemuriscv64:~/STAP# ./jdk/bin/java -version
Error occurred during initialization of VM
Unsupported satp mode: sv57. Only satp modes up to sv48 are supported for now.


Testing:

Tier1-3 passed without new failure on unmacthed (release).

-------------

Commit messages:
 - Backport 8297697: RISC-V: Add support for SATP mode detection

Changes: https://git.openjdk.org/riscv-port-jdk17u/pull/53/files
 Webrev: https://webrevs.openjdk.org/?repo=riscv-port-jdk17u&pr=53&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297697
  Stats: 41 lines in 3 files changed: 40 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/riscv-port-jdk17u/pull/53.diff
  Fetch: git fetch https://git.openjdk.org/riscv-port-jdk17u.git pull/53/head:pull/53

PR: https://git.openjdk.org/riscv-port-jdk17u/pull/53