include: Update the OpenCL headers

include: Update the OpenCL headers

This syncs all our headers with their canonical versions from Khronos.
Of particular note, CL headers repo does not have cl.hpp and cl2.hpp has
been depricated all in favor of opencl.hpp which is the new canonical
header.  Fortunately, nothing in Mesa uses any of the C++ headers so
this shouldn't break anything.

Acked-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19816>