[OpenMP] Update OpenMP support document

Marks omp_target_is_accessible routine as done.

Author: nicebert

clang/docs/OpenMPSupport.rst

@@ -256,7 +256,7 @@ implementation.
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device                       | device-specific environment variables                        | :none:`unclaimed`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device                       | omp_target_is_accessible routine                             | :part:`In Progress`      | https://github.com/llvm/llvm-project/pull/138294                      |
+| device                       | omp_target_is_accessible routine                             | :good:`done`             | https://github.com/llvm/llvm-project/pull/138294                      |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device                       | omp_get_mapped_ptr routine                                   | :good:`done`             | D141545                                                               |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+