[docs] Add missing Clang release note.

Adding this on behalf of [email protected].

Author: tru

clang/docs/ReleaseNotes.rst

@@ -1052,6 +1052,7 @@ RISC-V Support
 - Note that the RISC-V Vector C intrinsics are still under development. The RVV
   C Intrinsic Task Group is working towards a ratified v1.0.
 - The rvv-intrinsic-doc provides `compatible headers <https://github.com/riscv-non-isa/rvv-intrinsic-doc/tree/master/auto-generated/rvv-v0p10-compatible-headers>`_ for transition from the previous implemented version to the current (v0.11) version.
+- Clang now supports `v0.11 RVV intrinsics <https://github.com/riscv-non-isa/rvv-intrinsic-doc/tree/v0.11.x>`_.
 
 CUDA/HIP Language Changes in Clang
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^