src/poky:libyaml: Amend CVE status as 'upstream-wontfix'

Use an existing defined CVE_CHECK_STATUSMAP key in
meta/lib/oe/cve_check.py in order to avoid following complaint from
BitBake:

  WARNING: libyaml-native-0.2.5-r0 do_create_spdx: Invalid detail "wontfix" for CVE_STATUS[CVE-2024-35328] = "wontfix: Upstream thinks there is no working code that is exploitable - yaml/libyaml#302", fallback to Unpatched

(From OE-Core rev: c66d9a2a0d197498fa21ee8ca51a4afb59f75473)

Signed-off-by: Niko Mauno <niko.maunovaisala.com>
Signed-off-by: Richard Purdie <richard.purdielinuxfoundation.org>