Don't forcefully enable RISC-V 'V'ector support, version 1.0 is neither
supported by clang 13 nor by our kernel.

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -293,9 +293,9 @@ else()
     # we add the gcv compiler flag, which then requires the CPU (now when using
     # either compiler) to support V.
     if(HWY_CMAKE_RVV)
-      list(APPEND HWY_FLAGS -march=rv64gcv1p0)
+      #list(APPEND HWY_FLAGS -march=rv64gcv1p0)
       if(${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
-        list(APPEND HWY_FLAGS -menable-experimental-extensions)
+        #list(APPEND HWY_FLAGS -menable-experimental-extensions)
       endif()
     endif()
   endif()