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
@@ -470,23 +470,6 @@ else()
     endif()
   endif()  # HWY_CMAKE_ARM7
 
-  if(HWY_RISCV)
-    # Add the gcv compiler flag so that RVV is available as a baseline target.
-    # Without this, Clang 19+ can still use RVV via runtime dispatch.
-    if(HWY_CMAKE_RVV)
-      if(RISCV_XLEN EQUAL 64)
-        list(APPEND HWY_FLAGS -march=rv64gcv1p0)
-        add_link_options(-march=rv64gcv1p0)
-      elseif(RISCV_XLEN EQUAL 32)
-        list(APPEND HWY_FLAGS -march=rv32gcv1p0)
-        add_link_options(-march=rv32gcv1p0)
-      endif()
-      if(${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
-        list(APPEND HWY_FLAGS -menable-experimental-extensions)
-      endif()
-    endif()
-  endif()
-
   if (HWY_WARNINGS_ARE_ERRORS)
     list(APPEND HWY_FLAGS -Werror)
   endif()
