c11: Update the values of enum mtx_plain, mtx_recursive, mtx_timed to make sure mtx_r...

c11: Update the values of enum mtx_plain, mtx_recursive, mtx_timed to make sure mtx_recursive != mtx_plain | mtx_recursive

According to c11 standards, there is 4 variant of mtx_init parameter,
mtx_plain
mtx_timed
mtx_plain|mtx_recursive
mtx_timed|mtx_recursive

Directly use mtx_recursive is not a thing, so we need make sure mtx_plain and mtx_plain|mtx_recursive are not equal,
So now we choose the values from Android c11 threads.h for enum mtx_plain, mtx_recursive, mtx_timed, to make sure
c11/threads.h be more c11 conformance, and can raise error when the type parameter of mtx_init are not one of
mtx_plain
mtx_timed
mtx_plain|mtx_recursive
mtx_timed|mtx_recursive

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18445>