Merge patch series "riscv: Add vendor extensions support for SiFive"

Cyan Yang <cyan.yang@sifive.com> says:

This patch set adds four vendor-specific ISA extensions from SiFive:
"xsfvqmaccdod", "xsfvqmaccqoq", "xsfvfnrclipxfqf", and "xsfvfwmaccqqq".

Additionally, a new hwprobe key, RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0,
has been added to query which SiFive vendor extensions are supported on
the current platform.

Signed-off-by: Cyan Yang <cyan.yang@sifive.com>
Link: https://lore.kernel.org/r/20250418053239.4351-1-cyan.yang@sifive.com
* b4-shazam-merge:
  riscv: hwprobe: Add SiFive xsfvfwmaccqqq vendor extension
  riscv: hwprobe: Document SiFive xsfvfwmaccqqq vendor extension
  riscv: Add SiFive xsfvfwmaccqqq vendor extension
  dt-bindings: riscv: Add xsfvfwmaccqqq ISA extension description
  riscv: hwprobe: Add SiFive xsfvfnrclipxfqf vendor extension
  riscv: hwprobe: Document SiFive xsfvfnrclipxfqf vendor extension
  riscv: Add SiFive xsfvfnrclipxfqf vendor extension
  dt-bindings: riscv: Add xsfvfnrclipxfqf ISA extension description
  riscv: hwprobe: Add SiFive vendor extension support and probe for xsfqmaccdod and xsfqmaccqoq
  riscv: hwprobe: Document SiFive xsfvqmaccdod and xsfvqmaccqoq vendor extensions
  riscv: Add SiFive xsfvqmaccdod and xsfvqmaccqoq vendor extensions
  dt-bindings: riscv: Add xsfvqmaccdod and xsfvqmaccqoq ISA extension description

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>